Diagnostic Aids
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST procedures to ensure all electronic engine control systems are working properly and DTCs are no longer present.
Perform this test when directed by QUICK TEST. This test is only intended to diagnose the following components and circuits:
- 4x4 Low Range Switch
- Wiring Harness Circuits For 4x4 Low Range Switch
- Powertrain Control Module (PCM)
Low range indicator illuminates when vehicle is shifted to 4x4 low range gear. On Manual Shift On The Fly (MSOF) 4x4 systems, 4x4 low switch provides ground path to complete 4x4L indicator circuit. On Electronic Shift On The Fly (ESOF) 4x4 systems, 4x4 module provides ground path to complete 4x4L indicator circuit. Status of 4x4 low range circuit is sent to PCM by instrument cluster through Standard Corporate Protocol (SCP) communications. There is no circuit from 4x4 low circuits to PCM.