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Home >> GMC >> 1995 >> Forward Control 4.3 Z, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 6.5L Diesel. >> Diagnostic Trouble Code Charts >> DTC 46, Malfunction Indicator Light (Mil) Circuit Fault >> Notes
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DTC 46, Malfunction Indicator Light (Mil) Circuit Fault: Notes

MIL should always light when ignition is on and engine is not running for 2 seconds. PCM controls MIL by providing a ground path. DTC 46 will set when:

Or 

PCM will default to no MIL.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. This step checks PCM's ability to command MIL.
  2. This step determines if an open is present in ignition feed circuit or MIL control circuit.