I own a 2016 Citroën C4 Picasso MK2 1.6 BlueHDI 120 ETA6 S&S VIN VF7**************[VIN obfuscated, can be read by forum staff] and recently experienced an unusual starting issue.
Description of the Failure
A few days ago, after stopping the car for just one minute, I tried to restart it, but it wouldn't fire up.
- The dashboard looked completely normal (no odd warning lights before attempting to start).
- The engine did not turn over/crank.
- I was able to roll up the windows and eventually had to tow the car home.
When I first connected my diagnostic tool (Diagbox), the car initially showed multiple errors, including a loss of communication with the gearbox (ETA6). After several start attempts, it entered economy mode.
1. Battery Check: I suspected the battery might be the cause. I tried replacing it with a new one, but the problem persisted, so I returned it.
2. Current Battery Status: The original battery is now fully recharged and shows a voltage of 12.73V.
3. Current Diagnosis (Diagbox): I managed to exit economy mode and clear all fault codes, but one error persists:
- Communication Fault with the ABS/ESP Module.
Considering that the car will not start and the only persistent fault is the loss of communication with the ABS/ESP, what is the most likely cause? Where should I begin checking (fuses, wiring harness, specific module location)?
