Code 43: Fuel Supply System
NOTE:
If driveability problems are present, test fuel-related components. See SYSTEM/COMPONENT TESTS
article in the ENGINE PERFORMANCE Section.
- If referred here from CODE 1, go to next step. Turn ignition off. Remove BACK-UP fuse (10-amp) from underhood fuse/relay box for 10 seconds to reset ECM. Warm engine until cooling fan comes on. With transmission in Neutral, raise engine speed to 3000 RPM and hold for 2 minutes. Check ECM for fault codes. If Code 43 is present, go to next step. If Code 43 is not present, problem is intermittent. Check for poor connections at ECM and HO2S connectors. Test drive vehicle and retest.
- Turn ignition off. Connect ECM Test Harness (07LAJ-PT3010A ) between ECM and ECM harness connectors. See Figure . Wait 2 minutes. Install jumper wire between test terminals A6 and A26. Turn ignition on while measuring voltage between test terminals D14 (+) and A26 (-).
- If 0.1 volt or less is present as ignition is turned on, go to step 5). If more than 0.1 volt is present as ignition is turned on, remove HO2S cover. Disconnect HO2S connector. Measure voltage between the HO2S wiring harness connector terminals "A" and "B". See Fig 1 .
- If 0.1 volt or less is present, repair open circuit in White wire between HO2S and ECM connector. If more than 0.1 volt is present, reconnect HO2S electrical connector. Warm engine until cooling fan comes on. With transmission in Neutral, raise engine speed to 3000 RPM and hold for 2 minutes. Measure voltage between test harness terminals D14(+) and A26(-). Voltage should be more than 0.5 volt at wide open throttle and less than 0.5 volt when throttle is quickly released. If voltage is as specified, test fuel-related components. See SYSTEM/COMPONENT TESTS article in this section. If voltage is not as specified, replace HO2S.
- If 0.1 volt or less was present as ignition was turned on in step 3), remove HO2S cover. Disconnect HO2S connector. Measure voltage between test terminals D14 (+) and A26 (-). If more than 0.1 volt is present, replace HO2S. If 0.1 volt or less is present, disconnect ECM connector "D" from wiring harness.
- Measure voltage between test terminals D14 (+) and A26 (-). If more than 0.1 volt is present, repair short in White wire between ECM connector and HO2S. If 0.1 volt or less is present, replace ECM and retest.