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My 2003.5 has been down for a turbo project for 2.5 years. Getting it all buttoned back up finally, but now I'm getting c1232, c1233, c1248, and c1255.
I know 1255 means internal ebcm failure, but could there be a connector or ground I missed when reassembling to also cause this? Or does the 1255 mean ebcm is bad guaranteed? The troubleshooting guides I found basically all end with "replace EBCM" but I would like to confirm I didn't just miss something before I do that.
As AjdSpain stated, he replaced the ignition switch and solved the issue. HOW THE HELL can an Ignition switch cause that???> LOL! Well it can and here is how. The EBTCM has two power supplies. 12 VDC Battery & 12 VDC IGNITION SWITCH supplied. The ignition switch has several contacts in side that get BURNT and can cause it to output a LOT LESS VOLTAGE than 12 VDC that it needs to output.
SO, Instead of just throwing parts at it, get a meter and read the supply voltages and ground to make sure that you are getting all the necessary voltages and grounds to allow the module to function as designed.
REMEMBER,, the C5 modules HATE low voltages.
Start there and see what you get. EVERY FUSE in a C5 (all modern cars) has two test points on top of the fuse. Read both of those test points to chassis ground and make sure that the voltages on BOTH of those test points equals what battery output is.
Check the modules GROUND path to chassis ground with an OHM Meter. The ground should be ZERO Ohms or very close to zero ohms.
That's the very first place to start.
Last edited by Bill Curlee; Aug 9, 2018 at 10:29 AM.
I sent you a schematic but it does not seem like the pin out that you posted. Where did you get that pin out?? Did you actually measure the voltages on those pins and how much different was it than actual battery voltage measured at the battery terminals. The voltages that you listed would be in spec. if that is what was read.
12.6 - 12.4 on the ground pins, which matched the battery. I got that schematic from searching here. Will compare it to your emailed version later today and see if there are any differences. Regardless, I seem to have a good power, good switched power, and two good grounds at the connector as that schematic indicates I should.
Jack
Last edited by cptinjak; Aug 11, 2018 at 03:02 AM.
There really should NOT be any VOLTAGE readings on a ground pin unless the ground is open. Don't know why you would take voltage readings on a ground pin.. Turn power OFF and see what the resistance reading is on the ground pins. Should be zero ohms
EBCM Code Help
