Table 1

Circuit Description
- The Passlock TM system is designed to prevent vehicle operation if the correct ignition key is not used to start the vehicle. The ignition key will allow the lock cylinder to turn, which allows the Passlock sensor (located inside of the ignition switch assembly) to send an analog voltage code to the Body Control Module (BCM). If the BCM receives the correct analog voltage code from the Passlock TM sensor the BCM will send a Class 2 serial data password to the Powertrain Control Module (PCM) / Vehicle Control Module (VCM) which will allow the vehicle to start.
- The Body Control Module (BCM) supplies a 12 Volt supply voltage, a data line, and a ground circuit to the Passlock TM system.







Test Description
3. This step isolates the circuit 1140 short to ground to the harness.

NOTE: the TBC fuse also supplies the Keyless entry.

5. This step determines if the short is in the BCM.
6. This step determines if the fuse randomly opened or was the result of the RFA.
8. This step checks for an open in circuit 1140.
10. This step checks for an open in ground circuit 1850.
12. This step checks for an open in circuit 39 between BCM C1 connector B2 and IP fuse block J7.
14. This step checks Class 2 communication between the BCM.
15. This step checks if the fuse is open and if there is voltage at Cl, B9. If voltage is present the BCM is replaced by default. All conditions which would cause a non DTC failure have been checked.
18. This step determines if the short to ground is in the harness.
20. This step determines if the short to ground is in the BCM or other circuits fed by circuit 41.
21. This step determines if the CRUISE fuse randomly opened or there is a short to ground in the BCM.