Try this, Engine does Not Crank - Starter Solenoid Does Not Click - Monitor Ignition Accessory Voltage - keywords DTC DTCs no start On rare occasions, the ECM may not command the starter relay on, resulting in an engine no crank concern with no DTCs. When in the crank position during the concern, the Starter Relay Command on the Tech 2 will display "Off" even though the Crank Request Signal displays "Yes".
If the SI diagnostics do not isolate the cause of this concern, monitor the Ignition Accessory Signal Parameter on the Tech 2 during the concern. This parameter should display "Off" when in the crank position and "On" when in the accessory and run positions. If it reads "On" while in the crank position, monitor the accessory voltage circuit from the ignition switch to the BCM during the concern. If voltage is present on this circuit when in the crank position, inspect the circuit for a short to voltage with both ends of the circuit disconnected. If the circuit is not shorted to voltage, replace the ignition switch for evaluation.
Post back if this works, or what you find.
Monday, December 22nd, 2008 AT 4:30 PM