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ABS Light On and Possible DTCs - keywords C1225 C1226 C1232 C1233 C1276 C1277 EBCM EBTCM electrical indicator MIL sensor speed

Subject:ABS Light On and Possible DTCs

Models:1999-2004 Buick Century, Regal
2000-2004 Chevrolet Impala, Monte Carlo



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

Condition/Concern:

ABS light coming on and codes C1225, C1226, C1232, C1233, C1276 and/or C1277 are found in the EBCM. These codes may be current, but are usually stored as history codes.

Recommendation/Instructions:

Two areas of wire chaffing or rub through have been reported and verified. Both are near the left front corner of the engine compartment.

  1. If the wheel speed sensor wires are tight where they pass under the front of the transmission side cover, chaffing can occur as the powertrain moves on its mounts. This can be seen best from under the vehicle or from within the left front wheel well.
  2. At the air conditioner dryer canister the ABS harness splits. If this split is tight against the dryer canister bracket, the unprotected wires can chafe as the powertrain moves on its mounts. This can be easily seen from the top of the engine compartment, left front.

Correction: Repair any damaged wires and reroute in such a way as to prevent any further chaffing.

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.