I can help you if you can measure stuff.

 

Hi Liviu2004, I can measure voltages etc. It maybe easier for me to buy the complete ecu kit, however the bcm ident letters are my main concern of getting the correct one for equipment fitted? I would get the security code and program the vin in the bcm but again, this is almost the same as buying a complete kit ?

 

You will have same problem. Dont shoot the parts cannot yet. I will post something tonight.

 

Thanks mate, wiring diagrams would help me. I will be able to find my way round then. If I had the security code I would try and program the vin back into the bcm

 

Lets clear some bad statements here.

BCM has lost its programming/vin Id and is bringing down the bus network by not being allowed to communicate
False
try and program the vin back into the bcm
Having a VIN in BCM makes no difference for engine start nor immo check

Lets get started. This car has an issue with CAN comm between: ECU - ABS - BCM - IPC (dash). BCM acts as a gateway, different bus speeds. I assume manual gearbox.
This is the plug of the ABS, contact off, wait 2 min, get ABS plug off, measure resistance between pins 15 and 26. Don't enlarge the pins, pick the right tools or measure from behind.
120 ohms. If you don't have this, time to measure continuity to BCM, or BCM itself.

ABS has another set of pins towards ECU. Just for the fun, measure continuity, at the ABS pump itself, continuity between these pins: Measure at ABS plug, 120 ohms between pins 14, 25.

Report back.

 

Hi Liviu2004, thanks for the info. I can only assume without any technical documentation on the vehicle regarding the vin and also was hoping it could of been that, wishful thinking!
I take it that there are some terminating resistors in the ABS and BCM? Can I just ask what the voltages are meant to be on the bus? I’m used to 2.4v and 2.6v on what I work on. I would also be interested to look at a schematic of the bus network just for my own interest?

 

Terminating 120 ohms resistors are in engine ecu and bcm for hscan and bcm and ipc for lscan. Standard canbus physical interface including voltages as you say.

 

this is my corsa c auto canbus schematic. Some pin errors in.

 

And the oem single line diagram.

 

If you have an oscilloscope, put it on:

 

Top man thank you, I will measure them when it isn’t hammering down outside. It’s strange on Vauxhall’s how all the control units on this system are still communicating with solus if there is a bus issue.

 

Diag is on kline. For each module except radio and radio display. On this car, canbus is exclusive internal use only. You don’t get hscan and lscan in diagport.

 

Oh ok that makes more sense..

 

Finally got to look at the motor. After all the info provided I managed to do some in-depth testing. There was a wire tucked nicely away in the conduit near the engine lifting eye. It must of had the smallest of pin pricks in it, that allowed oxidisation to occur and build up a very high resistance. Thanks Liviu2004. Thought I would give your forum some feedback. ??