TB11 - Check 4X4 Signal From Generic Electronic Module

- Key "OFF".

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Key "ON", engine "OFF".

- Observe voltage between test pin 42 and test pin 40/60 at the breakout box while cycling the 4x4L switch.

- Does the voltage cycle?

Yes -- Replace PCM. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to TB12. TB12 - Check For Intermittent Circuit Fault