Ignition Switch: Description and Operation

Fig 1 Ignition Lock Cylinder:

Fig 2 Ignition Switch -- Viewed From Below Column:

NOTE: After testing starter solenoid and relay, test ignition switch and wiring. Check all wiring for opens or shorts, and all connectors for being loose or corroded.

IGNITION SWITCH
When the ignition switch is in the START or RUN position, it connects circuit A1 from fuse 5 in the Power Distribution Center (PDC) to circuit A21.

Circuit A21 feeds circuit F87 through the 9 amp positive temperature coefficient (PTC No.1) in the junction block. Circuit F87 supplies voltage to the Torque Convertor Clutch (TCC) solenoid, EVAP/Purge Solenoid, EGR Solenoid, and EVAP leak detection pump solenoid. Circuit F87 also supplies battery voltage to the coil side of the fuel pump relay and connects to the junction block.

IGNITION INTERLOCK
All vehicles equipped with automatic transaxles have an interlock system.
- The system prevents shifting the vehicle out of Park unless the ignition lock cylinder is in the OFF, RUN or START position.
- In addition, the operator cannot rotate the key to the lock position unless the shifter is in the park position.

LOCK KEY CYLINDER
The lock cylinder is inserted in the end of the housing opposite the ignition switch. The ignition key rotates the cylinder to 5 different detents:
- Accessory
- Off (lock)
- Unlock
- On/Run
- Start