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.
Diagnostic Aids
1993 GMC Value Van 4.3 Z, StandardSECTION Diagnostic Aids
Code 43 can be caused by a faulty knock sensor connection at ESC module or ECM. Also, check controller-to-ECM signal line for an open or short to ground.
CODE 43 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION
| Application | ECM Terminal | Wire Color |
|---|---|---|
| All With 4L60-E Transmission Knock Signal | B15 | Dark Blue |
| All With 4L80-E Transmission Knock Signal | D5 | Dark Blue |
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.