Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Does the scan tool show any DTCs? | -- | Refer to Instrument Cluster System Check in instrument panel, gauges and console | |
2 | Does the front axle engage when the four wheel drive (4WD) control lever is in the 4WD position? | -- | Refer to Front Axle Will Not Engage | |
3 | Using the scan tool, under special test in instrument cluster, command the 4WD indicator lamp ON. Does the lamp come on? | -- | Refer to Instrument Cluster System Check in instrument panel, gauges and console | |
4 |
Does the scan tool show switch status yes? | -- | ||
5 |
Does the test lamp light? | -- | ||
6 | Replace the front axle actuator/switch. Refer to Electric Motor Actuator Replacement in Front Drive Axle. Is the repair complete? | -- | System OK | -- |
7 |
Does the test lamp light? | -- | ||
8 | Replace the VCM/PCM. Refer to VCM Replacement/Programming for 4.3L or Powertrain Control Module Replacement/Programming for all other engines Is the repair complete? | -- | System OK | -- |
9 |
Does the test lamp light? | -- | ||
10 | Locate and repair CKT 1695 (BLK/WHT) for a short to ground. Is the repair complete? | -- | System OK | -- |
11 | Locate and repair CKT 1695 (BLK/WHT) for an open between the switch and the PCM/VCM. Is the repair complete? | -- | System OK | -- |
