04 05 Cadillac CTS SRX STS Buick Rendezvous LaCrosse No Crank No Start - kw DTC ECM ECU key MIL theft deterrent P1631 VTD

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

Vehicle will exhibit three concerns:

1. No Crank/No start.
2. Key not stuck.
3. "Starting disabled", " Remove key message" (Cadillac only) on the radio. Buick Rendezvous will say Security and LaCrosse will say starting disabled on display.

No other conditions/P-codes, except possibly a P1631, should be present. If other conditions are present, then published diagnostics should be performed

Reprogram ECM with latest calibration in TIS 2000.

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.

(2004 Cadillac CTS) and (2004 Cadillac SRX) and (2004 Buick Rendezvous) and (2005 Cadillac CTS) and (2005 Cadillac SRX) and (2005 Cadillac STS) and (2005 Buick Rendezvous) and (2005 Buick Lacrosse)