DTC P0136: Heated Oxygen Sensor (Ho2S) No. 2 Circuit Malfunction
- Inspect exhaust system for damage or leaks. Repair as necessary and retest system. If exhaust system is okay, turn ignition off and connect scan tool to Data Link Connector (DLC). Start engine and go to next step.
- Operate vehicle under normal driving conditions for 5 minutes. Observe HO2S No. 2 output voltage and short term fuel trim using DATA LIST mode on scan tool. Record readings. If HO2S No. 2 output voltage reading is less than 1.275 volts, go to next step. If reading is more than 1.275 volts, check for open between HO2S No. 2 and PCM (Blue or Pink wires on Esteem, or Light Green/Black or Yellow wires on Swift). If wiring is okay, check for faulty HO2S No. 2. Repair as necessary. Retest system.
- If short term fuel trim varied between -20 and +20 percent, go to next step. If short term fuel trim does not vary between -20 and +20 percent, check fuel system. See DTC P0171: FUEL SYSTEM LEAN, OR P0172: FUEL SYSTEM RICH .
- Check Blue wire or Pink wire on Esteem, Light Green/Black wire or Yellow wire on Swift for any opens, shorts or poor connections. Repair as necessary. If wiring and connections are okay, replace HO2S No. 2. Retest system.