T-Roc Coolant Leak & ECU Issues Need Expert Help

Having experienced similar symptoms with a 2020 VW Golf 1.5 TSI, the coolant leak combined with engine overheating often points to a failing water pump or compromised cooling system connections. The diagnostic trouble code linked to a communication fault typically indicates the engine control unit is not receiving accurate temperature readings. In my case, the root cause was a damaged wiring harness connecting the coolant temperature sensor to the control unit. The corroded connector was causing intermittent communication issues, leading to incorrect temperature readings and cooling system malfunction. The repair required: Complete diagnostic scan, Replacement of the wiring harness, New coolant temperature sensor, System pressure testing, Control unit software update This is considered a serious issue that needs immediate attention, as continued overheating can lead to severe engine damage. The connectivity issue between the sensors and control unit must be resolved to prevent recurring problems. A proper diagnosis should include: Full system scan for fault codes, Pressure testing of the cooling system, Testing of all sensor connections, Verification of control unit functionality The combination of physical leaks and electronic faults suggests multiple systems need inspection by a technician with dealer-level diagnostic equipment.

Thanks for sharing your detailed experience. Your repair steps seem similar to what I am dealing with. The wiring issue causing connectivity problems between the control unit and sensors matches my symptoms exactly. Did the fix hold up over time? Would really help to know what you ended up paying for the complete repair, as I need to budget for this. Getting my car checked next week and want to make sure I am not being overcharged. Have you noticed any other data link problems or CAN bus related issues since the repair was done? My main concern is making sure all control unit communication gets fully restored, not just a temporary fix.

Since getting my T-Roc repaired last month, the control module communication error has been completely resolved. The root issue turned out to be much simpler than initially feared, a faulty cable connection was causing the data link disruption between components. The fix cost 95€, which covered diagnosing and repairing the defective plug connection. The software glitch symptoms completely disappeared after the repair. The diagnostic trouble codes have not returned, and the engine temperature readings are now consistently accurate. The cooling system is working perfectly with no communication faults between the control unit and sensors. The key was finding a technician who properly diagnosed the wiring issue instead of jumping to more expensive component replacements. Their systematic approach to testing the data link connections saved both time and money. No additional CAN bus or control module problems have surfaced since the repair. The initial symptoms you described match what I experienced, so having the wiring connections thoroughly checked would be a good starting point before exploring more costly repairs.

Following up on my repair experience, I finally got the car fixed at a different shop that specializes in VW diagnostics. The CAN bus testing revealed exactly what was suspected, a damaged wiring connector causing intermittent communication faults between the control module and cooling system sensors. The total repair came to 750€ including: Complete car diagnostics scan, Wiring harness replacement, New temperature sensors, System pressure test, Control module recalibration, Fresh coolant After 2 weeks and 1000km, no more check engine lights or overheating issues. The connectivity issue is fully resolved and temperature readings are stable. The coolant leaks have stopped completely. The new shop did proper testing of all control module communications before and after the repair. Their systematic diagnostic approach made the difference compared to my previous mechanic who kept missing the root cause. Getting specialized diagnostics equipment involved was worth the extra cost to fix it right the first time.