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.

SYS.OK|MANUAL.DB● LIVE

HOMESERVICE MANUALSGMC1995RALLY G2500, 4.3 ZREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODES - 5.7LTROUBLE CODE CHARTSDTC 43: KNOCK SENSOR WITH SPARK CONTROL MODULEDIAGNOSTIC AIDS

1995 GMC Rally G2500, 4.3 Z

Diagnostic Aids

1995 GMC Rally G2500, 4.3 ZSECTION Diagnostic Aids

Code 43 can be caused by a faulty knock sensor connection at ESC module or engine control module. Also, check controller-to-control module signal line for an open or short to ground.

Fig 1: Code 43 Schematic ("C" & "K" Series) Knock Sensor With Spark Control Module

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

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.