I'm trying to diagnose a 2000 C5 coupe. It has the ABS and traction control lights on + the DIC's service vehicle message. Scanned for codes with HPT, pasted below.

I've tried searching, but haven't found the answer yet. Any ideas on where to go with this?

Thanks in advance!

[Restraints] B1001 - Option Configuration Error (History) (Immature)
[Restraints] U1040 - Loss of Class 2 Communications with ABS (History) (Current) (Immature)
[HUD] B0521 - (History) (Immature)
[Convenience] B2282 - (History) (Immature)
[Convenience] B2284 - (History) (Immature)
[Convenience] B2283 - (History) (Immature)
[Convenience] B2285 - (History) (Immature)
[Convenience] U1064 - Loss of Communications with DIM (History) (Immature)
[Convenience] U1096 - Loss of Communications with IPC (History) (Immature)
[Convenience] U1016 - Loss of Class 2 Communication with VCM (History) (Immature)


Continuous Tests
Misfire: Complete
Fuel System: Complete
Comprehensive Component: Complete


Once Per Trip Tests
Catalyst: Incomplete
Heated Catalyst: n/a
Evaporative System: Incomplete
Secondary Air System: Incomplete
A/C System Refrigerant: n/a
Oxygen Sensor: Incomplete
Oxygen Sensor Heater: Incomplete
EGR System: n/a

 

Get the codes for the DIC-the should be ABS codes.

 

History codes displayed = u1096h, 1064h
Current code displayed = u1040hc

TCS module showed no communication.

Where is this located? I'm going to hunt around online for diagnostic and/or replacement info on this. Any insight or advice?

 

TCS is the traction control system. I'd start by checking the connector on the EBCM.

 

Here is the diagnostic process to find out why a module isn't communicating with the system.



By the way, did you see a TCS-No Com message when you displayed the codes on the DIC? If you didn't that might mean the module is communicating with the system. When a module is dead you usually see No Com instead of any codes for that module. The U1040 indicates there was a communications issue between the IPC and the TCS module but not necessarily with the whole system.

Bill

 

The DIC did display a TCS-no comm message.. I'll check power and ground to it - betting it's dead and needs to be replaced though.. *sigh*

 

When I had my EBCM out of my car for repair, I got the no comm message as well as 1040 code, good luck man

 

Well well, we may have good news..decided to look at the obvious first and took a look at the fuse block. The two large fuses for the ABS module were missing. Since I didn't have any of the large style fuses laying around, I swapped a few over from other locations to see what would happen.

With fuses in place, I got communication with the TCS module and (after clearing), two codes were set on startup: P0480C (I'm sure this is because I stole a fuse from the cooling fan) and C1243H. The name I found for this code is 'BPVM Pump Motor Stalled.'

I'm searching now and seeing threads about applying 12v directly to cycle the motor. I'm a little skeptical about that fixing things here... I'll keep searching and looking to see what I can figure out. Is this a common problem and a good solution for it?

 

The ABS resets itself when you turn off the engine and then starts fresh on the next engine start. You might want to drive the car for a couple hundred feet and get it over 10 mph then pull over and without shutting the engine off use the DIC to run the codes again. If the pump motor is still stalled the code will show as current.

The motor is in the BPMV. Before directly feeding B+ to the BPMV you should use a DMM and check the resistance between the motor circuits and the BPMV case/ground. If you get any reading less than infinite resistance you need to replace the very expensive BPMV.

Some people have hooked up 12 V to the motor to get it to run. If the unit passed the resistance test above this might work to get a sluggish motor to run better. If it doesn't run when you hit it with 12V then you need to replace the BPMV. If it runs the motor may be freed up and work properly afterwards. Usually when an electric motor is stalled or is running slower than it is supposed to run it draws a lot of current which could mean the pump motor relay which is inside the EBCM and provides power to the BPMV is getting fried and you are close to seeing the dreaded C1214 code.

Bill

 

Why were the fuses MISSING would be my 1st question!!

 

^+1
..and since they were missing, wouldn't the ABS/TC lights always been on?

 

No clue why they were missing! I've only had the car for about a week now, just getting the few issues it has diagnosed and taken care of.

ABS and TCS lights were on from the first time I drove the car.

I picked up replacement fuses today - I'll have a chance to take a look at it on Sunday.

 

Any follow up on this issue?

 

I've been pretty tied up with work, haven't had a chance to take a look at it any further just yet. I'm expecting to have a little more time mid-week to check it out.

 

Had a few free minutes to at least take it for a run. Cleared codes, drove the car, got a 1243C code. Had a buddy use a Tech 2 to cycle the motor a few times... sounded a little better after a few times, but the issue still persists.