DTC P0135: Heated O2 Sensor (Ho2S) No. 1 Heater CKT 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. On models with manual transmission, measure voltage (backprobe) between PCM harness connector "B", terminal No. 11 (Pink wire) and ground. On models with automatic transmission, measure voltage (backprobe) between PCM harness connector "D", terminal No. 19 (Pink wire) and ground. If voltage is 10-14 volts, go to next step. If voltage 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 voltage is 0-1 volt, check for an intermittent problem. See TESTS W/O CODES article. If voltage is not as specified, check for poor PCM harness connection. If connection is okay, replace PCM. Retest system.