98 STS C1255

[Res STS]

I have code C1255, Electronic brake and traction control module (EBTCM) internal malfunction, on my 58,000 mile 98 STS after the original battery went dead and installing a new Delco battery. The service manual indicates this is expected, but I have cleared it several times via OBD, but the ABS and traction control warning lamps come back on every restart along with DIC messages: Service Steering and Service Stability System.

An experienced Cadillac tech told me the EBTCM is touchy and he fairly regularly can't reset C1255 and has to replace the EBTCM after battery disconnect/reconnects.

I did not do anything dumb during the battery replacement, but I'm dumbfounded to look at about a $600 repair risk if you change the battery.

Yes, the cable connectors are clean -- they look like new.

Anyone else have experience with this?

[Logan]

Here is the diagnostics......go from there I guess....

There have been times....where a code could not be cleared unless using a GM Tech 2...

Anyway.....here is the code....

DTC C1255 EBTCM Internal Malfunction

Circuit Description

This DTC identifies a malfunction within the EBTCM.

Conditions for Setting the DTC

An internal EBTCM malfunction exists.

Action Taken When the DTC Sets

A malfunction DTC is stored.

The ABS/TCS/Stabilitrak® is disabled.

The ABS indicator is turned ON.

The TRACTION CONTROL indicator is turned ON.

The DIC displays the SERVICE STABILITY SYS message.

For some DTC C1255xx, the Magna Steer® is disabled and the DIC displays the SERVICE STEERING SYS message.

Conditions for Clearing the DTC

The condition for DTC is no longer present and you used scan tool Clear DTCs function.

The condition for DTC is no longer present and you used the On-Board Clear DTCs function.

The EBTCM does not detect the DTC in 50 drive cycles.

Diagnostic Aids

When the scan tool displays the DTC, 2 more numbers follow the DTC. Note the 2 numbers and any other DTCs. The 2 numbers with the DTC are an engineering aid in order to determine the cause of the internal malfunction.

A DTC C1255e2 can be caused by a battery or module connector disconnect. Inspect for a recent battery disconnect or module connector disconnect before replacing the EBTCM.

A DTC C1255m5 can be set along with any wheel speed sensor DTC. Diagnose any wheel speed sensor DTCs before replacing the EBTCM.

Make sure the integrity of the connection between the EBTCM and the BPMV is secure, tight, and free from corrosion.

[Res STS]

Thanks for the info, Logan.

OBD doesn't show the C1255xx codes (unless I don't know enough to retrieve the xx codes).

I was wondering if OBD would not clear all codes and it sounds like you're saying this is correct, that a scan tool may be needed.

I'm still wondering about the cause and effect of this problem. I did have the original battery which was absolutely trouble free, no hint of weakness, but after leaving the car sit in the garage part of Saturday and all of Sunday, the battery was extremely weak: the keyless entry did not open the lock (also strange as I did not lock the car in the garage!) and the courtesy lights would not come on at all.

It took a couple days to get a new Delco battery. So, just for grins I tried charging the battery with a Smart-Charger and a 10 amp charger. For the first day, the battery held very little charge, but after that, it took a full charge according to my Smart-Charger. I removed the battery and it's held a charge outside of the car for a week now.

I wonder if something in the wiring or EBTCM malfunctioned and drained my original battery, but that is hard to imagine with the key off and out and with battery run-down protection. Red herring or related events?

After a week with the new battery, I've had no battery problems.

One more thing that happens with C1255 that isn't listed, the trans starts out from a stop in 2nd gear. Manual selection with the shifter will not bring in first gear either.

I'll let you know what happens as I sort this problem.