XLR Tachometer SI Diagnostic Revision - accessory control dash display electrical fuse gauge ground ignition inaccurate indicator information inoperative instrument intermitent IPC module no operation

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

If a tachometer does not operate, looking at SI reveals incorrect information. The description is incorrect. SI states that the tachometer signal is class 2, when the signal is actually hard wired.

The correct circuit is listed in document ID 1116024 and is listed as circuit 121, a white wire. There is not a check for circuit 121 and no reference to the schematic under the trouble tree for the TACH being in-op. If the tachometer goes through the sweep cycle on key up the IPC is not the concern.

There was a poor female pin fit at connector C3 , pin D8 for circuit 121. See document number 919157 for more information. Repair the circuit from the PCM to the IPC to correct the concern.

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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. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(04 Cadillac XLR)

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