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 MANUALSHONDA1991ACCORD DX, 2D COUPE, STANDARDREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODESDIAGNOSTIC CODESCODE 43 - FUEL SUPPLY SYSTEM
1991 Honda Accord DX, 2D Coupe, Standard
Code 43 - Fuel Supply System
1991 Honda Accord DX, 2D Coupe, StandardSECTION Code 43 - Fuel Supply System
- Turn ignition off. Remove appropriate fuse for 10 seconds to reset ECU. See CLEARING CODES . Start engine, and warm to normal operating temperature (cooling fan comes on). Raise engine speed to 3000 RPM, and hold for 2 minutes. Verify if CHECK ENGINE light is flashing Code 43. If Code 43 is present, go to next step. If Code 43 is not present, problem is intermittent. Check connections at O2 sensor, related circuits and at ECU.
- Turn ignition off. Connect ECU Test Harness between ECU and connector. Wait at least 2 minutes with ignition off. Turn ignition on. Measure voltage between terminals D14 (+) and A26 (-) as soon as ignition is turned on. If more than .1 volt was present, go to next step. If less than .1 volt is present when ignition is first turned on, go to step 4).
- Disconnect 4-wire connector from O2 sensor. Measure voltage at O2 sensor connector between terminals "C" (-) and "D" (+). If voltage is more than .1 volt, replace O2 sensor. If voltage is less than .1 volt, repair open in White wire between ECU terminal D14 and O2 sensor.
- Disconnect 4-wire connector from O2 sensor. Measure voltage between terminals D14 (+) and A26 (-). If voltage is more than .1 volt, replace O2 sensor. If voltage is less than .1 volt, disconnect test connector "D" from main wire harness.
- Measure voltage between terminals D14 (+) and A26 (-). If voltage is more than .1 volt, repair short in White wire between ECU terminal D14 and O2 sensor. If voltage was less than .1 volt, substitute a known good ECU. If condition is corrected, replace original ECU.
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.
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.