Caddy 2K won't start, no communication from OBD

[Emmaryauto99]

Hi there, anyone had this one before?? my 2011 1.6tdi caddy wouldn't start, like I'd not pressed the clutch then after several tries it clattered from the relays and started, 5 miles later engine cut out ground to halt and won't start again, AA came and his computer wasn't connecting to the OBD saying no communication, towed me in to my workshop and my code reader won't communicate either, a VW tech had a look at it this aft and he says all relays & fuses are fine thinks it'll be bad earth, broken wire or similar from the ecu and told me to strip the scuttle out, wipers etc and have a look for anything dodgy, has anyone been here before to point me in right direction before I strip it? Thanks in advance!!

[GreenV8S]

No experience with that vehicle, but if it was me I'd be looking for physical access to the ECU, researching which pins provide power and ground and seeing whether the corresponding pins on the wiring harness connect accordingly. That's going to be a lot quicker and easier than basically stripping the interior of the car in the hopes of spotting a damaged wire - which seems like a huge task with minimal chance of finding a wiring fault even supposing that's what the problem was.

[mighty kitten]

You should have power and earth on the 16pin diag port . A quick easy test is to find a sensor like maf or map and check for the 5v reference feed to prove the ecu is powered up before digging around the fuse / relay boxes

[Emmaryauto99]

Thanks guys I'll let u know what I find 👍

[Sardonicus]

mighty kitten said:

You should have power and earth on the 16pin diag port . A quick easy test is to find a sensor like maf or map and check for the 5v reference feed to prove the ecu is powered up before digging around the fuse / relay boxes

This ^ ECU not powered often over looked