Shift Light (Manual Transmission)
- These tests assume a shift light problem exists. Use this procedure only if the light will not illuminate, or illuminates all the time.
- Turn ignition on, with engine off. Note shift light. Shift light should not be on. If light is on, check for a short to ground between bulb and ECM or for bad ECM.
- With ignition on and engine off, ground test terminal "B" of Data Link Connector (DLC). Malfunction Indicator Light (MIL) should start to flash and shift light should come on. If light comes on, go to next step. If MIL does not flash, perform DIAGNOSTIC CIRCUIT CHECK as described in BASIC TESTING
article in this section.
- If shift light does not come on, ground Tan/Black light driver wire at ECM terminal using a jumper wire. See Fig 1. If light still does not come on, check for blown GAGES fuse, blown bulb or open circuit between fuse and ECM. If light comes on when grounding ECM terminal with a jumper wire, problem is a bad ECM connection or bad ECM.
Courtesy of GENERAL MOTORS CORP.