WL statesman not cranking.

[Jon Rothwell]

OK, so here is where we are at. 190 Alloytec V6, At first cranking was intermittent, even when jumpering the starter relay, changed the starter motor and problem solved, put in a new battery just to be sure. Now it starts by jumping the starter motor relay with the ignition on, we just removed the relay case and manually trigger the relay. Now it will crank and start at first with the ignition on and manually triggering the relay, after that it will restart from the key even when the doors are locked and re-locked, and after the security light comes on. BUT, after about 10 minutes it will not start from the key again, and needs to have the relay triggered with the ignition on to start. It comes up with a heap of error codes, but even re-setting those makes no difference, after 10 minutes it will not re-start from the key and all the codes come back. We get ABS, CANBUS, FUEL LEVEL, ECU, SRS, ABS and Stability control failures. Engine runs great and other than this issue it is a great car to drive once you get it started and clear the codes.
Any suggestions please?

 

[gtrboyy]

I've been caught out a few times by bad earths being the cause of weird issues for vt-vz models

 

[Jon Rothwell]

Checked all the earths, replaced battery, read codes (only code I get is no communication to ECU, which goes away when I force start.), checed keys and security system. Am not getting a pulse to starter relay, but, after I force start it all works fine for 10 or so minutes, then it's back to a forced start again. I hate to say ECU fail, but it's looking more like that.

 

[gtrboyy]

You can bypass the relay or even unplug the 2 wire plug put power to purple/white trace wire to see if starter cranks easily then work your way back.

Last car checked I got caught out by battery terminals...multimeter & dash said 12.8 volts turn key click click click with new starter....terminals looked decent but changed as checked everything else.Something so simple!!!

 

[Jon Rothwell]

Yep, starts when bypassing relay. All codes reset after that and will start from the key and seems normal, but 10 minutes later after being turned off it is back to no start, no pulse to relay, and multiple codes from SRS, ABS, Stability control, Low Fuel, no ECU Communication. At this point you can disconnect the ECU and the car does not even realise it is gone.

 

[Trevor loves holden.]

Alternator not over charging.

 

[Jon Rothwell]

When it starts it runs and drives fine, no issues or errors at all. Alternator is within spec according to my scan tool. It's just the starting pulse that seems to be the issue and after another afternoon mucking around I'm leaning towards an issue with the BCM. Tomorrow I'm going to rip it out and see if I can get into it.

 

[Jon Rothwell]

Problem was solved by changing the ECU, BCM, key etc as a full set. Later testing showed that the ECU was sometimes not communicating which was probably due to a faulty capacitor which we could not replace due to the ECU construction. Car now runs fine.