DTC P0139 / P2A01
Precautions: General safety (00)
DTC Detecting Condition and Trouble Area
| DTC detection condition | Trouble area |
|---|---|
|
P0139: O2 Sensor Circuit Slow Response (Sensor 2) Ratio of measured A/F sensor-2 signal voltage and modeled A/F sensor-2 signal voltage is less than specified value when engine running. (3 D/C detecting logic) |
•A/F sensor-2 and/or its circuit
•A/F sensor-2 heater and/or its circuit •Exhaust system •Air intake system •Fuel system •ECM |
|
P2A01: O2 Sensor Circuit Range / Performance (Sensor 2) Ratio of measured A/F sensor-2 signal voltage and modeled A/F sensor-2 signal voltage is higher than specified value when engine running. (3 D/C detecting logic) |
Circuit Diagram
| [A]: | ECM connector (View: [a]) | A3: | A/F sensor-2 signal circuit (IPN) | B2: | A/F sensor-2 heater drive circuit |
| A1: | A/F sensor-2 signal circuit (RT) | A4: | A/F sensor-2 signal circuit (RE+) | 1. | ECM |
| A2: | A/F sensor-2 signal circuit (APE) | B1: | A/F sensor-2 heater power supply circuit | 2. | A/F sensor-2 |
DTC Troubleshooting
| Step | Action | Yes | No |
|---|---|---|---|
| 1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
|
|
| 2 |
DTC check
Is there any DTC other than P0139 and P2A01?
|
Go to troubleshooting for applicable DTC.
|
Go to Step 3.
|
| 3 |
A/F sensor-2 signal circuit check
1)Check “A1”, “A2”, “A3” and “A4” circuits according to Step 3 of A/F Sensor-2 Check:D16AA.
Is check result OK?
|
Go to Step 4.
|
Repair or replace defective wire harness.
|
| 4 |
Exhaust system and air intake system check
1)Check exhaust system and air intake system for clogging or leakage.
Is check result OK?
|
Go to Step 5.
|
Repair or replace defective part(s).
|
| 5 |
A/F sensor-2 heater power supply circuit and drive circuit check
1)Check “B1” and “B2” circuits according to Step 1 – 2 of A/F Sensor-2 Check:D16AA.
Is check result OK?
|
Go to Step 6.
|
Repair or replace defective wire harness.
|
| 6 |
Fuel injector check
1)Check fuel injectors.
Is check result OK?
|
Go to Step 7.
|
Faulty injector(s) or its circuit.
|
| 7 |
A/F sensor-2 replacement
1)Replace A/F sensor-2.
2)Clear DTC.
3)Set ignition “OFF”.
4)Check DTC.
Is DTC P0139 or P2A01 still detected?
|
Replace ECM and recheck DTC.
|
End.
|