1999 Cadillac Seville second gear take off commanded

Transmission problem
1999 Cadillac Seville V8 Front Wheel Drive Automatic

code c1255? Trac controll abs light on has bat volts to ebcu 2 hot all time 1 key on
Do you
have the same problem?
Friday, February 12th, 2010 AT 6:51 PM

1 Reply

This code is pretty cut and dried, although if you are experiencing second gear starts, I don't show that as a symptom.

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.


Did you perform the ABS Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - ABS

Are any EBTCM DTCs present other than C1255xx?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 3

Turn OFF the ignition.
Disconnect the EBTCM connector.
Check for damaged, pushed out, or miswired terminals.
Was any damage found?
Go to Step 4
Go to Step 5

Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Diagnostic System Check - ABS

Replace the EBTCM. Refer to Electronic Brake Control Module Replacement.

Did you complete the repair?
Go to Diagnostic System Check - ABS

#PIC4036A: DTC C1255 With Various Sub Codes - keywords EBTCM ICCS TCS - (Mar 12, 2007)

Subject: DTC C1255 with Various Sub Codes

Models: 1996-1999 Buick Park Avenue

1997-1999 Buick Le Sabre

1997-1999 Cadillac Deville

1997-1999 Cadillac Seville

1997-2000 Cadillac Eldorado

1997-2000 Chevrolet Corvette

1997-1999 Pontiac Bonneville

This PI was superseded to update PI, removeing phone number to Delphi Tech support. Line has been disconnected and no longer in use for this concern. Please discard PIC4036.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Along with the C1255, a 2 digit Sub Code will set. The first digit is a Letter, and the 2nd digit is a number. Note that only the Tech 2 will display these sub codes, using the On Board Diagnostics through the Drivers Information Center on Cadillac and Corvette WILL NOT display sub codes.

Here is a list of the Sub Codes that may set:

E0, E1, E2, E3, E4, E5, E6, E7 M0, M1, M2, M3, M4, M5, M6, M7

Probable Cause: Each sub code represents a specific malfunction. Most sub codes set due to a malfunction internal to the EBTCM, and can be repaired by replacing the EBTCM. However, EBTCM replacement is NOT always necessary when DTC C1255 is set. Here is a list of exceptions where a fault external to the EBTCM will set C1255.

C1255 E2: This Sub Code may set due to a loss of battery or ground to the EBTCM.

Battery Cable disconnect
EBTCM Fuse Pull
EBTCM harness disconnect
Weak or Discharged battery
Any other interruption of battery or ground to the EBTCM
C1255 E2: Can also set when an EBTCM is first installed on a vehicle. C1255 E2 will be stored as a history code only, and WILL NOT turn on the ABS light. A typical service scenario is when an EBTCM is replaced for a DTC other than C1255. The vehicle again returns with the ABS light on, and C1255 E2 is set as a history DTC along with the original DTC which brought the vehicle in for service. The servicing technician is erroneously convinced that the new EBTCM is defective.

Replace the EBTCM for C1255 E2 only when a source of a battery disconnect cannot be identified and was not set due to EBTCM replacement.

C1255 M5: This Sub Code indicates that the EBTCM has detected a malfunction in the one of the Wheel Speed Sensor Circuits, and sets along with Wheel Speed Sensor DTCs (C1221 thru C1235). Disregard C1255 M5 and perform diagnostics for the other wheel speed DTCs. Only replace the EBTCM if all other wheel speed sensor diagnostics have been exhausted and the source of the DTCs cannot be identified.

C1255 E4 and E6 set together: This sub code combination sets when the pump motor ground circuit has detected B+. This condition can occur if the BPMV ground circuit is shared with other components and the ground bolt is loose or disconnected. These other components are seeking ground, then back-feed into the EBTCM thru the BPMV.

If the sub code(s) are included in one of the exceptions listed above, repair the external condition, then clear the code and verify that C1255 does not reset. If the sub code(s) are NOT one of the exceptions listed above, replace the EBTCM.
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Monday, February 15th, 2010 AT 10:49 PM

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