DTC P0135 - Ho2S No. 1 Heater Circuit Malfunction
NOTE:
Before replacing HO2S No. 1, inspect sensor for contamination. If contamination is present, determine cause and repair before installing a new HO2S No. 1.
- Turn ignition off. Disconnect HO2S No. 1 harness connector. Using an ohmmeter, measure resistance between terminals No. 3 and 4 of HO2S No. 1. See Fig 1 . If resistance is 2.0-100 ohms, go to next step. If resistance is not as specified, replace HO2S No. 1. Retest system.
- Reconnect HO2S No. 1. Turn ignition on. Using a voltmeter, measure voltage (backprobe) between ground and PCM harness connector "B", terminal No. 11 (Pink wire). If reading is 10-14 volts, go to next step. If reading is not as specified, check Black/White wire or Pink wire for an open, Pink wire or Pink/Black wire for a short to ground or poor HO2S No. 1 harness connection. Repair as necessary. If wires and connections are okay, replace PCM. Retest system.
- Start engine and allow it to reach normal operating temperature. Using a voltmeter, measure voltage (backprobe) between ground and PCM connector "B", terminal No. 11 (Pink wire) with engine idling. If reading is 0-1 volt, check for an intermittent problem. See TESTS W/O CODES article. If reading is not as specified, check for poor PCM harness connection. If connection is okay, replace PCM. Retest system.