DTC P0135: Heated O2 Sensor (Ho2S) No. 1 Heater CKT Malfunction
- 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 11.7-14.3 ohms, go to next step. If resistance is not as specified, replace HO2S No. 1. Retest system.
Courtesy of SUZUKI OF AMERICA CORP.
- Reconnect HO2S No. 1. Turn ignition on. On models with 3-speed automatic or manual transmission, measure voltage (backprobe) between ground and PCM harness connector "B", terminal No. 23 (Pink wire). On models with 4-speed automatic transmission, measure voltage (backprobe) between ground and PCM harness connector "A", terminal No. 19 (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 open, Pink wire for short to ground, or poor HO2S No. 1 harness connection. Repair as necessary. If wires are okay, replace PCM. Retest system.
- Start engine and allow to reach normal operating temperature. On models with 3-speed automatic or manual transmission, measure voltage (backprobe) between ground and PCM harness connector "B", terminal No. 23 (Pink wire). On models with 4-speed automatic transmission, measure voltage (backprobe) between ground and PCM harness connector "A", terminal No. 19 (Pink wire). 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.