This may relate. Ideally if you could have the system scanned for codes and see if any are stored, that may offer something as well.
#PIC3300: ABS Light On DTC C1226 or Unwanted ABS or TCS Activation 1996 - 2000 Eldorado 1997 Seville 1997 - 1999 Deville - kw brake accelerate - (Dec 15, 2004)
Subject: ABS Light On DTC C1226 or Unwanted ABS or TCS Activation 1996 - 2000 Eldorado 1997 Seville 1997 - 1999 Deville
The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
ABS lamp on with a DTC C1226 and/or unwanted TCS or ABS activation may be caused by Electromagnetic Interference (EMI) in the right front wheel speed sensor harness induced from the rear bank of the secondary ignition wires.
Correct any concerns which exist with the secondary ignition wires or spark plugs. If no secondary ignition concerns are evident, inspect the harness routing of the secondary ignition wires. Shielding the harness on the right side has not been consistently successful. The technician should restring the wheel speed circuits from the EBTCM to the wheel speed sensor jumper harness connector on the right front side. A shielded harness part number 12140077 can be used on the right side. Install two twisted pair (Part #12140077) harnesses soldered together at the non-connector end to make one harness. Route the harness down the right frame rail, under the core support to the EBTCM.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.
(1996-2000 Cadillac Eldorado) and (1996-2000 Cadillac Eldorado ETC) and (1997 Cadillac Seville SLS 1997 Cadillac Seville STS) (1997-1999 Cadillac Deville 1997-1999 Cadillac Deville De'Elegance 1997-1999 Cadillac Deville Concours)
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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Wednesday, November 18th, 2009 AT 9:54 PM