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For 1990-2009 cars only

4WD Inoperative Erratic Fuel Gauge SIR Light Service Stability Message - keywords 4.2L 5.3L ABS C0186 C0196 C0327 C0455 case communication connector inop IPC LH6 lamp light P0452 P0453 P0461 P0462

Subject:4WD Inoperative, Erratic Fuel Gauge, SIR Light, Service Stability Message

Models:2004-2007 Buick Rainier
2002-2007 Chevrolet Trailblazer, Trailblazer EXT, Trailblazer SS
2002-2007 GMC Envoy, Envoy Denali, Envoy XL, Envoy XUV
2002-2004 Oldsmobile Bravada
2005-2007 Saab 97x



This PI was superseded to update Condition/Concern. Please discard PIT3208C.


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

Condition/Concern:

A vehicle may exhibit: 4WD inoperative, SIR lamp, erratic fuel gauge operation and/or a Service Stability Message. Possible DTCs are C0186, C0196, C0327, C0455, P0452, P0453, P0461, P0462, P0463, P0464 and or U1088. A possible cause of these symptoms is a loose connection or backed out terminal(s) at the C101 connector, a 38-way connector mounted along the under hood fuse block. This harness may be routed tightly around the UBEC that could induce any of the concerns listed.

Recommendation/Instructions:

All terminal connections should be checked in this connector for integrity. Female terminals should be inspected for pin drag and Male terminal should be fully seated in the body cavity of the connector. Be certain that no terminals are bent or damaged in any way. Re-route the harness to prevent future harness and/or connector strain.

Note:  When servicing this connector special care should be made not to damage other terminals. Fully seat the connector squarely with both hands and then latch the locking portion of the connector (CPA). Do not use the lock mechanism on the connector to pull the connector halves together as this may cause terminals to bend or a poor connection.

Please follow this diagnostic or repair 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.