Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC 46, Malfunction Indicator Light (Mil) Circuit Fault: Notes
1995 GMC Suburban K2500, 7.4 NSECTION 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:
- Ignition voltage on MIL control circuit when PCM is requesting MIL on.
Or
- No ignition voltage on MIL control circuit when PCM is requesting MIL off.
PCM will default to no MIL.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- This step checks PCM's ability to command MIL.
- This step determines if an open is present in ignition feed circuit or MIL control circuit.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.