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JAECOO (ITALY) GENERAL PROBLEMS: DEFECTS, DIAGNOSIS, AND CHECKLISTS FOR WORKSHOPS — HUB 2025/2026

Updated October 2025 — edited by Gianni Tritella. This official technical guide “hub” collects and professionally analyzes the most frequent problems of Jaecoo vehicles in Italy — J5, J6, J7, and J8 — all currently with turbocharged petrol engines . It is designed for mechanics, auto electricians, and diagnosticians who want to understand in detail recurring symptoms, specific DTCs, and test procedures related to ADAS, DCT transmission, heating system, and NVH trims . You'll also find a practical checklist for workshops and direct links to in-depth articles by model , with real-life cases, diagnostic strategies, and references to official technical campaigns.

Useful Insight: JAECOO J7 PROBLEMS (ITALY 2025–2026): REAL FAULTS, DTCs AND TECHNICAL DIAGNOSIS

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🌍 Context: Italy: range and after-sales network

The Jaecoo brand—controlled by the Chinese group Chery Automobile —has officially entered the Italian market in 2025 with a range of next-generation SUVs, starting with the Jaecoo J7, equipped with a 1.6-liter turbocharged gasoline engine and a DCT dual-clutch automatic transmission . All versions destined for Europe are exclusively internal combustion engines , although the platform is designed to accommodate hybrid and plug-in powertrains in the future.

The brand's stated goal is to compete with European manufacturers in the C-SUV and D-SUV segments by offering premium features, advanced infotainment, and latest-generation ADAS . However, the Italian after-sales network is still expanding: new dealerships and official service centers will be gradually opened in 2025-2026, which means independent workshops will need to:

• stay up to date on the technical documentation and diagnostic protocols of the Chery-Jaecoo group;
• check the actual availability of spare parts through official channels and independent distributors;
• maintain traceability of interventions, TSBs and software updates, given the young age of the brand;
• invest in training on ADAS, DCT and electronic network management systems (CAN, Gateway, BCM).

Overall, the arrival of Jaecoo represents a new technical opportunity for the Italian market, but also a diagnostic challenge : many workshops are collecting initial data on ADAS behavior, calibrations, gear shift strategies, and NVH . This guide was created precisely to take stock of these experiences and provide a single, up-to-date and reliable framework .

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🚨 ADAS and DMS: invasive interventions and calibration

Initial findings in the workshop indicate marked steering corrections from the Lane Keeping Assist (LKA) and frequent alerts from the Driver Monitoring System (DMS), especially on narrow roads or with poor road markings. The solution involves rigorous calibrations , targeted software updates , and a repeatable road-test protocol .

🎯 Technical objectives

• Restore trajectory consistency and centering without excessive steering corrections.
• Reduce false positives of DMS/attention assist in real-world use conditions.
• Document with pre/post reports: DTCs, software versions, calibration results and road test results.

🧪 Typical symptoms and root causes

• “Jolting” traction or lane pull with LKA active → possible front camera misalignment , parameters not learned after windscreen, wheel toe out of tolerance.
• Frequent DMS warnings (tiredness/inattention) → camera positioning , internal lighting , dashboard reflections , sensitivity settings.
• Intermittent ADAS messages in rain/twilight → windshield quality / wiper cleaning area , condensation or slow dirt , missing software updates .

🔧 Prerequisites before calibration

• Wheel geometry checked and within tolerance; tire pressure correct (four wheels).
• OE/approved windshield , correct location/positioning of the camera bracket , clean and dry windshield (inside/outside).
• Power and ground stable; no active DTCs on ABS/ESC, BCM, gateway.
• Environment: Flat surface, uniform illumination , compliant targets and distances according to manual.

🧭 Calibration procedure (general diagram)

1. Full scan (ADAS, ABS/ESC, BCM, gateway) and pre-report saving.
2. Static calibration of the front camera with a dedicated target (distance and height as per specification). Verification of the yaw/pitch/roll offsets .
3. If applicable, perform radar calibration (front/rear) with reflectors or metal panels.
4. Dynamic calibration on a suitable route (well-marked lines, constant speed). Respect the travel times/minimum travel times indicated by the instrument.
5. Instrumented road test : urban and extra-urban stretch with irregular signs to evaluate the robustness of the learning.
6. Final scan and save post report ; attach setup photos and condition sheet (weather, light, temp., tire pressure).

🧰 Parameters and DTCs to monitor

• Frame camera : alignment status , learned values , lane confidence , warning counters .
• Steering angles : zero value, steering angle offset , consistent with yaw-rate and wheel speed (ABS).
• Typical DTCs :
  • C1xxx – camera/radar not calibrated or out of range ;
  • U0xxx – communication loss/intermittent (ADAS↔ABS/BCM/gateway);
  • B1xxx – body/HMI (cluster, DMS, profile settings).

🛣️ Road-test protocol (repeatable)

1. Section 1 – Optimal lines (5–10 km) : activate LKA; check centering , corrections <±5° steering wheel on straight lines, no “ping-pong”.
2. Section 2 – Degraded signage : broken lines, slight curves; note warnings and stability corrections.
3. Section 3 – Urban : sensors exposed to stop & go; DMS check (false positives) with natural and artificial light.

Minimum output : event logs (timestamps), photos/clips, behavior notes, pre/post update reports.

⚠️ Common mistakes to avoid

• Calibration with convergence out of specification or incorrect pressures.
• Targets not level or distances “by eye”: always use laser/meter and levels.
• Non-OE windshield or camera bracket not perfectly positioned/glued.
• Skip dynamics when required: LKA remains aggressive or unstable.

🗂️ Customer Deliverable/Warranty

• Pre/post OBD reports (DTCs, ECU versions, calibration results).
• Photo setup target and alignment screens OK .
• Signed road test report with routes, weather, average speed, notes.

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🧠 Software, OTA and HMI: maturity and parameterization

The first software releases for Jaecoo vehicles marketed in Italy highlighted a physiological need for updates —particularly for ADAS management, infotainment system fluidity, and HMI (Human Machine Interface) consistency. For the workshop, this means adopting a structured diagnostic and update protocol , with complete traceability of ECU versions and post-intervention results.

🎯 Technical objectives

• Keep ECU versions aligned with the official releases published on the Jaecoo/Chery technical portals.
• Ensure stable infotainment (no reboots or lags in ADAS, climate, navigation, user profiles menus).
• Prevent false errors or warnings due to unlearned parameters after updates or battery resets.

🧩 Recurring symptoms reported

• Temporary lag or freezes on the ADAS or infotainment screen, especially after incomplete OTA updates.
• Resetting user profiles or losing radio/climate settings on reboot (sync bug).
• Recurring system messages on DMS or LKA, due to failed initialization of camera/radar modules after update.
• Long boot times (>30 s) or random reboots while driving.

⚙️ Operational best practices for workshops

1. Full ECU scan with pre-update report (ADAS, HMI, BCM, Gateway, TCU, ECM).
2. Check available OTA and Technical Service Bulletin (TSB) status: note current and target version.
3. Back up parameters and user profiles if required by the diagnostic tool.
4. Proceed to update ECU via official tool or OTA network in stable environment: battery voltage ≥ 12.5V, no line interruption.
5. After the update, start the basic settings (e.g. camera, steering angle sensors, climate control, gateway).
6. Complete the procedure with a post-update road test to verify ADAS/HMI consistency and the absence of new DTCs.

🧾 Documentation and traceability

• Archive diagnostic report (pre/post) with vehicle ID and software version of each ECU.
• Note the date, time, and tool used for the update (OTA or offline).
• If you fixed any obvious bugs (e.g., smoother ADAS, more responsive HMI), please briefly describe them in the notes field of your workshop management system.
• Keep a copy of the TSBs applied for future reviews or warranty checks.

🧠 Key metrics to monitor

Domain	Parameter	Scope
ADAS ECU	SW Version, LaneAssist Status, Calibration	Check for updates and correct camera/radar alignment
BCM / Gateway	Network sync, LIN/CAN load	Check network integrity after update
HMI / Infotainment	Boot time, freeze count, response delay	Evaluate system fluidity and interface stability

⚠️ Common mistakes to avoid

• Stop an OTA update or remove the key before it completes.
• Ignoring basic settings after ECU update causes false DTCs and ADAS warnings.
• Proceeding with updates without a stabilized power supply → risk of ECU brick.
• Failure to register the updated SW version → loss of traceability and warranty problems.

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⚙️ DCT transmission: behavior, reset and tests

DCT (dual-clutch) transmissions offer speed and efficiency, but are more sensitive during slow maneuvers , when starting on hills , and in high ambient temperatures . To reduce jerkiness, vibration, and shift delays, the shop must combine TCU updates , clutch learning , and thermal/NVH checks with a repeatable protocol.

🎯 Technical objectives

• Restore progressivity (kiss point clutches) and reduce engagement delays in D/R.
• Limit jerks/clonks when maneuvering and low-load judder .
• Maintain oil temperatures within the optimal window and prevent thermal derating .

🧪 Typical symptoms & root causes

• Jerking or “elastic” when starting → clutch learning not performed after interventions, brake/accelerator pedal misalignment, loose engine/gearbox mounts.
• Hot D↔R delay → oil viscosity out of specification, overtemperature, slow response from electro-hydraulic filter/valves.
• Clonk in release/low load engagement → transmission/shaft clearances, CV joints, support bearings, engine mounts .
• Derating and thermal protection in urban summer → reduced heat exchange efficiency, fans not in target, clogged auxiliary radiator.

🧰 Operational best practices (logical order)

1. Initial diagnosis: TCU/ECM/ABS scan and parameter snapshot (rpm, load, oil temperature, clutch slip, circuit pressure).
2. Mechanical/NVH checks: engine/gearbox mounts, axle joints, transmission play; tire pressures and toe-in.
3. Thermal: check exchanger status, clean radiant pack, fan functionality; DCT oil T° rise/fall times.
4. Software: Check TCU release and TSB application if present.
5. Learning/Basic settings: perform kiss point learn , clutch touch point , adaptation reset according to manual.
6. Instrumented road test: mixed route with log; pre/post comparison of engagement times and slip.

⚙️ Adaptive clutches (generic procedure)

1. Bring DCT oil to 60–80 °C (range indicated by the instrument).
2. Vehicle on level ground, parking brake on, electrical consumers off.
3. Perform TCU adaptive resets → then learn kiss points for both clutches.
4. “ Creep learn ” procedure if applicable: D/R selection with brake hold, then gradual release according to instrument prompt.
5. Close with gear cycle (1→6/7 and back) in a straight line at constant gas.

📊 Key metrics to monitor (pre/post logs)

Parameter	Value/Target	Technical notes
DCT oil temperature	80–110 °C (urban use); <120 °C continuous	Above threshold → possible derating/protective slippages
Clutch slip A/B	≈0 rpm at full throttle; short peaks when engaging	Persistent slip → incomplete fit or wear
Circuit pressure	In TCU specification	Pressure drops → filtration/valves/electric actuators
Time D↔R	≤1.0–1.5 s	Hot delays → TCU/oil viscosity/heat exchange check

🛣️ Road test (repeatable protocol)

1. Slow maneuver on an 8–12% slope: 3 D↔R cycles with light braking; evaluate progression and delays.
2. Hill -Start Assist active: check creep and torque modulation without jerking.
3. Low load 30–60 km/h : check judder 1→2→3; monitor slip/pressure.
4. Extraurban driving at a stable temperature: check kickdown times and the absence of “elastic”.

Minimum output: parameter log, D↔R times, NVH notes, pre/post fit comparison.

🧾 DTCs and useful correlations

• P07xx (range/performance/press.) → hydraulic circuit/solenoid valves/TCU.
• P17xx (clutch A/B) → adaptive, wear, internal speed sensors.
• U0xxx (network) → TCU synchronism with ECM/ABS; check gateway and masses.

🧴 Fluid and maintenance

• Use the specific DCT oil indicated by the manufacturer (no mix) and respect the torques/volumes.
• Evaluate early replacement interval in severe urban/high temperature use.
• Inspect exchangers /lines: dirt on radiant pack = high T° = derating.

⚠️ Mistakes to avoid

• Perform learning with oil temperature out of range or low battery.
• Skip reset/adaptive after replacements (clutches, TCU, windshield with related ADAS calibration).
• Ignore engine/gearbox mounts : they generate false “gearbox faults”.

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🌡️ Thermal: cooling, intake/turbo, fuel

On compact turbocharged petrol engines, three critical areas impact reliability and drivability: cooling , intake/supercharging , and fuel delivery . A well-organized protocol avoids unnecessary replacements and reduces post-service visits.

🎯 Technical objectives

• Maintain stable operating temperatures (fluid/oil/intake air) in city and highway driving.
• Ensure air circuit pressure sealing and consistent boost control response.
• Ensure proper fuel flow and pressure , with smooth hot/cold starting.

🧪 Typical symptoms & possible causes

• Intermittent overheating in tailgate or A/C ON → fans not in target, radiator pack clogged, incomplete purge, thermostat/solenoid valve bypass.
• Gaps in acceleration , 2–3–4 jerks → micro-leaks on hoses/intercooler, dirty/out of range MAF/MAP, wastegate that “hunts”.
• High consumption and petrol smell when cold → positive LTFT corrections, dirty injectors, low rail pressure, slow pre-cat probe.
• Knock/advance limitation on low quality fuel → High IAT, intake valve carbonization (indirect injection/DI), ECT above target.

🔧 Workshop protocol (recommended order)

1. Basic diagnosis : ECM DTC reading + freeze-frame ; checking levels/contaminations (oil/coolant).
2. Radiator pack : visual inspection and cleaning from outside to inside (condenser → intercooler → radiator); air flow check.
3. Fans : actuator control from diagnosis, stage/duty-cycle control, abnormal absorption.
4. Circuit bleeding : vacuum fill procedure or manufacturer method; be careful of high points/HVAC branches.
5. Intake/boost : low-pressure smoke test ; intercooler and quick-release coupling leak test; pop-off valve/wastegate solenoid valve inspection.
6. Air sensors : MAF control and cleaning (only if equipped), MAF vs MAP consistency at idle/medium load.
7. Power supply : line/rail pressure to specification , pump flow test, night-time pressure drop; fuel quality and filters.
8. Instrumented road test : logging parameters and comparison with target ECU.

📊 Parameters to log (pre/post comparison)

Domain	Parameter	Target/Observations
Cooling	ECT (°C), IAT (°C), EOT (°C), Fan duty (%)	ECT stability; fan duty consistent with load/A/C; IAT not excessive vs. ambient
Supercharging	Boost required/actual, WG duty (%), STFT/LTFT	Limited boost deviations; fuel trim in range; WG without oscillations
Aspiration	MAF (g/s) at idle/3000 rpm, MAP (kPa), IAT	MAF↔MAP Consistency; Plausible Values ​​vs. Displacement (According to ECU Specification)
Fuel	Line/rail pressure, injection timing, O2/λ, Knock corr.	Rail in spec; O2 reactive; no persistent knock corrections

🛣️ Road test (repeatable protocol)

1. Urban warm-up (10–15 min): ECT/EOT ​​monitor, fan duty, any IAT peaks in the column.
2. Constant extra-urban (70–90 km/h): check consistency between requested/actual boost and fuel trim.
3. Medium load climb : observe WG duty and pressure holding; beware of power cuts from high ECT/IAT.
4. Overrun & Recovery : Check MAF/MAP transients and absence of “holes” in throttle response.

Minimum output: parameter log, radiant/joint pack photos, smoke/pressure test notes, pre/post cleaning or repair comparison.

🧾 Useful DTCs (indicative)

• P00xx — Air/MAF/MAP Circuit (Range/Performance, Plausibility).
• P01xx — Air/Temperature Sensors; P0128 (Thermostat, Low Operating Temp).
• P02xx — Cylinder injection/fuel trim; P0087 / P0089 (fuel pressure/control).
• P0234 / P0299 — overboost/underboost; P024x — wastegate/solenoid valve control.

🧴 Maintenance & targeted interventions

• Cleaning the radiant pack and restoring the air duct seals; important in summer/urban use.
• Check intercooler/hoses (pressure/tightness) and replace tired O-ring seals.
• Fuel service : new filter, check pump flow; in case of high LTFT, consider cleaning the injectors and checking the λ.
• Air sensors : MAF cleaning only if required; otherwise replace with a suitable spare part.

⚠️ Mistakes to avoid

• Incomplete bleeding after track work: creates seemingly “random” hotspots and DTCs.
• Replace turbo without having ruled out minimal leaks on intake/intercooler.
• Evaluate fuel trim without considering fuel quality and air temperature.
• Aggressive washes that bend radiator fins or push dirt into the core.

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🔊 NVH / FINISHES: WIND NOISE, ALIGNMENTS AND SEALS

Initial road tests and feedback from workshops have reported wind noise on some vehicles at highway speeds and small differences in body alignment that affect acoustic and vibrational comfort. These are NVH (Noise, Vibration & Harshness) fine-tuning issues typical of brands entering the European market, but they can be effectively managed with targeted diagnostics and micro-adjustments in the workshop.

🎯 Technical objectives

• Detect and correct sources of aerodynamic noise or localized vibrations above 100 km/h.
• Ensure gasket sealing and alignment consistent with OEM tolerances.
• Apply a standard NVH procedure to classify and document the type of noise perceived.

🧠 Most frequent critical areas

• A-pillars and rearview mirrors : turbulence and constant-speed rustling; check seals and plastic joints.
• Roof/rail bar profiles : slight resonances and vibrations above 110 km/h, often due to differences in tightening or deformed seals.
• Doors and door stops : seals not yet "settled" or partially compressed; the tape test and closing force check are useful.
• Front wheel arches : “drum” noises on draining surface → plastic fixings or brackets insufficiently tensioned.
• Rear area / tailgate : creaking on potholes → loose bumps, rubber buffers or interior panel clips.

🔧 NVH Diagnostic Protocol

1. Subjective listening + recording (directional microphone): note conditions (temperature, speed, wind direction, type of road).
2. Masking tape test : Apply masking tape to suspected gasket joints (doors, uprights, roof profiles). If the noise decreases, the problem is confirmed.
3. Check alignments with feeler gauge and OEM shims: hood, doors, tailgate, headlights, bumpers.
4. Inspect the gaskets : elasticity, signs of crushing or deformed sections; lubricate with technical silicone if necessary.
5. Check wheel arch , underbody, side member and windshield fastenings: tighten to specification.
6. Dynamic test : motorway stretch 90–130 km/h, radio off, air conditioning off, 3 laps in each wind direction.

📊 NVH Check Table (Workshop Example)

Area	Symptom	Corrective action
A-pillars / Mirrors	Constant hiss >100 km/h	Check gaskets, joints, and mirror thicknesses; perform any micro-realignment of the cover.
Roof profiles	Resonance above 120 km/h	Tightening the rail bar, checking the channel seal, inserting the anti-vibration device
Doorman	Air noise in the upper area	Seal lubrication, deformation check, hinge/stop adjustment
Wheel arches	Clicking or resonances on an irregular background	Check clips and bolts, apply anti-vibration washer
Tailgate	Crackling or popping sounds	Adjusting the stops/pads, checking the internal panel fixing

🧩 Recommended materials and tools

• NVH Technical Tape (for temporary insulation in aerodynamic tests).
• Feeler gauge sheets for door, hood and fender alignment.
• Neutral silicone lubricant for restoring the elasticity of seals.
• Acoustic stethoscope or directional microphone for isolating specific noises.

⚠️ Common mistakes to avoid

• Applying non-OE gaskets or “universal” profiles → modifies air flow and worsens noise.
• Overtightening rail bars or fixings → vibrations transferred to the roof.
• Using mineral greases on EPDM gaskets → premature deterioration.
• Not documenting weather conditions during testing → non-repeatable results.

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📦 SPARE PARTS AND DOWNTIME: BEST PRACTICES IN THE WORKSHOP

With the recent entry of the Jaecoo brand into the European market, the spare parts and after-sales network is still under development: supply lead times may vary depending on the channel, the type of component, and availability at the Chery group's central warehouses. For independent or multi-brand workshops, this requires proactive management of critical parts and clear communication with the customer to avoid disputes and excessive downtime.

🎯 Management objectives

• Minimize vehicle downtime through active planning of sensitive spare parts.
• Transparently manage customer-workshop communication and order tracking.
• Ensure alignment with Jaecoo/Chery warranty policies , particularly for electronic components and ADAS.

📊 “Sensitive” components with variable lead time

• ADAS sensors (radar, camera, DMS) – subject to limited availability, dedicated packaging, and import times.
• Windshield with camera housing and heater – often out of stock in the first months after launch.
• Exterior plastics and fastening clips – code differences between local and Asian versions.
• Interior trim and gaskets – suppliers ramping up production; risk of shade/batch mismatch.
• Electronic components (ECU, TCU, gateway) – subject to warranty restrictions and official replacement procedures.

🔧 Recommended operating strategies

1. Plan to pre-order components at risk of downtime (sensors, glazing, clips, plastics, ECUs) at least 10–15 days before your workshop appointment.
2. Create an internal database with equivalent or compatible aftermarket codes , validated with visual comparison and technical data sheet.
3. Manage spare parts with immobilization priority (1: mechanical; 2: electronic; 3: aesthetic): allows you to order by urgency.
4. Communicate realistic lead times to the customer and offer, where possible, a replacement vehicle or pick-up & delivery service.
5. Monitor TSB and update campaigns : Some components are replaced under warranty with improved releases.
6. Document each request with the date, supplier, tracking number, and photo of the part to avoid warranty disputes.

🧾 Traceability and customer communication

• Provide the customer with a time transparency sheet (order, estimated arrival, any supplier notes).
• In case of delay, please send a written update (email/SMS) with the new estimated date and replacement status.
• If the vehicle remains stationary, offer a photographic pre-diagnosis and a partial estimate to block the technical waiting time.
• Keep photos of installed/replaced components for warranty and internal CRM purposes.

📦 Recommended warehouse and partnerships

• Independent distributors specializing in Asian vehicles → often faster to import.
• Virtual warehouses (European portals with shared inventory) to reduce average downtime.
• Scheduled procurement contracts with official Jaecoo dealers → improve delivery SLAs.
• Create internal mini-stocks of compatible consumables (clips, gaskets, temperature sensors, air/pollen filters) based on initial workshop statistics.

⚠️ Mistakes to avoid

• Relying on unofficial portals without checking OE/aftermarket codes and VIN frame compatibility.
• Do not inform the customer of any import delays or backordered parts.
• Installing components of uncertain origin → risk of electronic failure and warranty voiding.
• Dismantling the vehicle prematurely without certainty of replacement part availability.

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🔌 Technical note: hybrid predisposition (extra-EU)

In non-EU markets , plug-in hybrid versions exist on similar platforms. In Italy, as of 2025, Jaecoo vehicles are internal combustion engines , but some electronic/network choices reflect the hybrid predisposition. It's useful to know this to correctly read the CAN and gateway topology, without confusing the HV domains with those present on Italian models.

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🧰 DIAGNOSIS: SYMPTOMS, DTCs, AND RECOMMENDED TESTS (VALID IN ITALY)

Diagnosis of Jaecoo vehicles in Italy requires a methodical approach: these are latest-generation combustion models, with electronic architecture derived from Chery hybrid platforms. Many apparent anomalies are not actual faults, but inconsistencies between control units , software versions, or incomplete calibration conditions. This section collects symptoms, troubleshooting codes, and workshop-verified tests to reduce analysis times and improve the quality of the repair.

1️⃣ RECURRING SYMPTOMS (ACTUAL WORKSHOP CASES)

• Invasive steering corrections from Lane Keeping Assist (LKA) or repetitive DMS warnings → camera not calibrated or ADAS update not performed.
• HMI / infotainment lag post-boot → release bug or adaptive memories not reset after OTA.
• Wind noises >110 km/h → roof profiles or seals not yet “settled”.
• Jerking or bumping when maneuvering (DCT) → incomplete adaptive TCU or soft gearbox mounts.
• Variable delivery times for spare parts → after-sales network in the process of being established, need for advance planning.

2️⃣ MOST FREQUENT DTCs AND CONTROL DOMAINS

Jaecoo electronic management adopts a multi-domain logic with a central gateway: codes often appear in a cascade and must be interpreted by priority. Below are the most common ones, divided by family.

Domain	Typical codes	Diagnostic area
CAN Communications	U0xxx	Loss of connection between ADAS, ABS, BCM, gateway – check ground and connectors
ADAS / Camera / Radar	C1xxx	Calibration error, misalignment, non-OE windshield, glare or lens condensation
Body / HMI / Comfort	B1xxx	Cluster, DMS, infotainment, gateway communications; parameter resets or version bugs
Thermal powertrain	P0xxx	MAF/MAP, boost, wastegate control, air/oil temperature sensors, lambda, rail pressure

3️⃣ RECOMMENDED TESTS (MULTI-DOMAIN PROTOCOL)

Applying a structured diagnostic workflow reduces interpretation errors and improves reporting accuracy. The following tests are valid for all Jaecoo thermal models currently on the market in Italy:

1. Full domain scan (ADAS / ABS / BCM / Gateway / ECM / TCU) and pre-intervention report for archiving.
2. CAN network analysis : check voltage 2.3–2.7 V, resistance 60±1 Ω at the bus ends, absence of noisy nodes or oxidized connectors.
3. Check ECU software versions and search for available TSBs or OTAs; update ADAS and TCU modules if recent releases fix known bugs.
4. ADAS calibration after windshield replacement, crash or alignment work: target alignment, ambient light 300–1000 lux, level plane.
5. Road test with 3-phase logging :
   • Urban: check DMS responsiveness and unsolicited ADAS shutdowns.
   • Extraurban: LKA stability, steering response, corrections <±5°.
   • Highway: Monitor wind noise, NVH vibrations and DCT thermal derating.
6. DCT : check adaptive TCU (kiss point, clutch touch point), oil temperature 80–110 °C, hydraulic pressures stable.
7. Thermal : smoke test of intake, intercooler, and hoses; check fan flow, thermostat efficiency, and fuel trim stability.
8. Final report : save logs, screenshot parameters, and document any post-update software releases.

📈 Key parameters to log (minimum log set)

Domain	Parameter	Reference Value/Range
ADAS	Steering angle offset, lane confidence, radar status	Offset ≤ ±1°, confidence ≥ 80%, radar OK
Powertrain	Boost Required/Actual, STFT/LTFT, IAT, ECT	Δ boost ≤ 0.15 bar, fuel trim ±8%, air T° < 50 °C
DCT	Clutch slip, hydraulic pressure, D↔R time	Slip ≈0 rpm, press. stable, D↔R ≤1.5 s
NVH	Internal noise (dB), Z-axis vibration (m/s²)	Noise < 68 dB, vibration < 0.3 m/s²

🧩 Advanced interpretation

• Multiple DTCs U0xxx/C1xxx → check gateway synchronization and ECU versions: it is often a software problem, not a hardware one.
• High fuel trim + P0299 (underboost) → check for leaks on hoses or dirty intercooler; don't blindly swap turbos.
• Judder DCT + P17xx → perform adaptive clutches; if learned values ​​are abnormal, check internal position sensors.
• ADAS lights active after OTA → always complete dynamic calibration: many systems remain “learning pending”.

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🧩 Quick checklist for workshops

Step	What to check	Outcome
1	Full ECU scan (ADAS/BCM/ABS/Gateway) + pre/post report	☐ OK ☐ NOK
2	Manual camera/radar calibration (static/dynamic)	☐ OK ☐ NOK
3	Software/OTA updates and basic settings	☐ OK ☐ NOK
4	Road test with logging (LKA/DMS, HMI)	☐ OK ☐ NOK
5	DCT: adaptive TCU, oil temperature, manoeuvre/hill test	☐ OK ☐ NOK
6	Thermal: smoke test, intercooler/sleeves, fans/thermostat	☐ OK ☐ NOK
7	Spare parts planning (ADAS sensors, clips, windshield with camera housing)	☐ OK ☐ NOK

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❓ FAQ

Are the Jaecoos ​​sold in Italy hybrids?

No: by 2025, the Italian range will only be internal combustion . Hybrid variants exist in non-EU markets, but are useful only as a technical reference.

Do “aggressive” ADAS improve with updates?

Yes: many fixes depend on software releases and calibrations. Always perform a pre- and post-update comparison road test.

Is the DCT defective?

Not necessarily: DCTs are sensitive to slow shifting and high temperatures. Check the adaptive TCU, oil temperature, updates, and engine/gearbox mounts.

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📌 Conclusions

For the Italian market, the areas to focus on are ADAS/HMI , DCT , engine thermodynamics and NVH/finishes , with a focus on replacement times . Use this HUB to navigate to model in-depth analyses (J5/J6/J7/J8) and update procedures based on real-world evidence collected in the workshop.