DTC 1: Primary HO2S (Sensor 1) Circuit Malfunction
- Reset the ECM/PCM (see page 11-468).
- Start the engine. Hold the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle for at least one minute before test-driving.
- Test-drive under following conditions.
- in MT, A/T: 2nd position
- accelerate using wide open throttle for at least 5 seconds, then decelerate for at least 5 seconds with the throttle completely closed.
Is the MIL on and does it indicate DTC 1?
YES |
- Go to step 4. |
NO |
- Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the primary HO2S (Sensor 1) and at the ECM/PCM. |
- Inspect fuel pressure (see page 11-430).
Is it normal?
YES |
- Go to step 5. |
NO |
- Check for fuel supply system (see page 11-561). |
- Let it idle for at least 1 minute before test-driving.
- Open the throttle wide open, then quickly release it.
- Measure voltage between ECM/PCM connector terminals A6 and A24.
ECM/PCM CONNECTOR A (31P)
Wire side of female terminals
| |
Is the voltage above 0.6 V at wide open throttle to 4,500 rpm (min-1) and below 0.4 V when the throttle is quickly released from 4,500 rpm (min-1)?
YES |
- Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM. |
NO |
- Go to step 8. |
- Turn the ignition switch OFF.
- Disconnect the primary HO2S (Sensor 1) 4P connector.
- At the Primary HO2S (Sensor 1) harness side, connect the battery positive terminal to terminal No. 4 and battery negative terminal to terminal No. 3).
- Start the engine.
- After 2 minutes, measure voltage between primary HO2S (Sensor 1) 4P connector terminals No. 1 and No. 2.
ECM/PCM CONNECTOR A (31P)
Wire side of female terminals
Is the voltage above 0.6 V at wide open throttle to 4,500 rpm (min-1) and below 0.4 V when the throttle is quickly released from 4,500 rpm (min-1)?
YES |
- Repair open or short in the wire between the ECM/PCM (A6) and the primary HO2S (Sensor 1). |
NO |
- Replace the primary HO2S (Sensor 1) (see page 11-554). |
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