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.
1992 GMC Value Van 5.7 K, AutomaticFACTORY OEM SERVICE PROCEDURE
All Except 4.3L Turbo & Models With 4L80-E Transmission
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- If conditions for a Code 34 exist, Scan tester will display YES. A knock signal should exist at idle unless an internal or system problem exists.
- Determines if system is functioning. Usually, a knock signal can be made by tapping on the exhaust manifold. If knock signal is not made, try tapping on engine block near sensor. On models with automatic transmission, it may be necessary to place gear selector lever in Drive.
- Because Code 43 sets when the signal voltage on the spark retard line remains low, this test should cause the signal on that line to go high. The 12-volt signal should be seen by the ECM as a no knock signal if the ECM and wiring are okay.
- This test determines if the knock signal is detected on the sensor-to-controller line or if the ESC module is at fault.
- If sensor line is routed too close to secondary ignition wires, the ESC module may see the interference as a knock signal.
- This checks ground circuit to module. An open ground will cause the voltage on the monitored line to remain constant at about 12 volts. This would cause the Code 43 functional test to fail.
- This should generate a knock signal to the controller. This determines if the ESC controller is operating correctly.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.