Diagnostic Test
- CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes >> Go To 2 No >> If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
- INSPECT JUNCTION BLOCK FUSE #18 Turn the ignition off. Remove and inspect Junction Block Fuse #18. Is the fuse open? Yes >> Replace fuse and retest. If fuse continues to fail inspect the wiring between the Junction Block and the Front Control Module for a short to ground. Perform «BODY VERIFICATION TEST - VER 1»(ref-212762-S01756696562005122700000) . No >> Go To 3
- (F941) IGNITION SWITCH OUTPUT CIRCUIT OPEN Turn the ignition on. Measure the voltage of the (F941) Ignition Switch Output circuit at the fuse input terminal. Is the voltage above 10.0 volts? Yes >> Go To 4 No >> Repair the (F941) Ignition Switch Output circuit for an open. Refer to «SYSTEM WIRING DIAGRAMS»(ref-163740) . Perform «BODY VERIFICATION TEST - VER 1»(ref-212762-S01756696562005122700000) .
- (F202) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN Turn the ignition off. Install Fuse #18 in the Junction Block. Remove the FCM from the Power Distribution Module. Turn the ignition on. Measure the voltage of the (F202) Fused Ignition Switch output circuit. Is the voltage above 10.0 volts? Yes >> Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(ref-212762-S01756696562005122700000) . No >> Repair the (F202) Fused Ignition Switch Output circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(ref-212762-S01756696562005122700000) .
Scheme 4
IGNITION SWITCH TEST AND REPAIR
If the key removal effort is excessive on a vehicle with a automatic transmission first adjust the shift linkage, (Refer to ADJUSTMENTS in appropriate TRANSMISSION article).
If the ignition switch effort is excessive remove the ignition key cylinder from the steering column. (Refer to KEY/LOCK CYLINDER ). Check the turning effort of the key cylinder. If the ignition key cylinder effort is excessive replace the key cylinder. If the ignition key cylinder operates properly look for the following conditions.
ELECTRICAL DIAGNOSIS
For ignition switch electrical schematics, refer to SYSTEM WIRING DIAGRAMS .
MECHANICAL DIAGNOSIS (KEY DIFFICULT TO ROTATE)
Vehicles equipped with an automatic transmission and a steering column mounted shifter: an interlock device is located within the steering column. This interlock device is used to lock the transmission shifter in the PARK position when the key cylinder is in any position and the brake pedal is not depressed.
Vehicles equipped with a manual transmission and a floor mounted shifter: on certain models, a lever is located on the steering column behind the ignition key cylinder. The lever must be manually operated to allow rotation of the ignition key cylinder to any position. If it is difficult to rotate the key to any position, the lever mechanism may be defective. This mechanism is not serviceable. If repair is necessary, the steering column assembly must be replaced. (Refer to COLUMN ).