Hi, I have recently purchased a v70 t5 geartronic as a non runner, with the hope of getting it going once again.
It was apparently running fine, then after it was left for a few weeks it would no longer start. The battery was removed and recharged, but still no joy.
When I took ownership, the battery was dead, so replaced it with a charged one (and carrying out testing with charger/jump leads/booster pack connected).
The engine cranks, but will not fire. It seems to be cranking fine, no obvious lack of compression and cambelt ok. First thing I noticed was no EML on the dash with ignition on, and unable to read codes with a generic obd reader. This led me to check fuses and relays for ECM feeds (all ok) and also the earth points on both front wings (a bit grotty but good contact to ground, removed and cleaned anyway). After this the EML decided to light up with the ignition on, so tried starting again but still no luck. Read fault memory again, none logged/showing on the obd reader. Tried starting with easy start through the air filter housing, fired for a brief moment then died again. Fuel level was low, but above the 'red', so topped up with 10 litres anyway. However, by the time we got back from the petrol station, the EML decided to stop lighting up again!! This time, no amount of fiddling with the earth point or wiring loom had any effect.
Other checks carried out - fuel in fuel rail under pressure, so pump/relay ok.
Tried cleaning immobiliser antenna contacts, and also swapped over antenna (assumed working ok as when attempted to crank with antenna removed from the barrel, the engine didn't even turn over).
Spark plugs worn, but not wet, so assume fuel not being injected.
Tested ECM relay with 9 volt battery, clicking open/closed ok.
So, on to the wiring diagrams...
Chassis to battery earth ok.
Engine to chassis earth ok.
Permanent 12v to ECM OK.
Ignition switched 12v to ECM ok.
Both earth wires from ECM ok.
With ignition on, the ECM is earthing the relay FMA2 (ECM relay)
Has voltage on CAN wires in and out of ECM and also in and out of the TCM (2.4/2.6v, from experience this is about right, but don't have a scope to check pattern)
Beginning to suspect ECM at fault, so removed and took apart, found a very small amount of water ingress which had started to corrode around a chip on the board. Carefully cleaned, dried and refitted ECM, still no joy.
Just wandered if anyone else has had similar issues, or could spread some light on this before I send the ECM away for inspection/ repair.
I know these cars can suffer with ETMs and DIMs, could the lack of EML be a red herring?? Sorry for the long post, thought it best to list everything I had done so far...
Dave
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