DTC P0071

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DTC P0071

B3E090201072W52

DTC P0071 | Ambient air thermistor circuit failure
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DETECTION CONDITION | Open circuit or short to power supply or GND in wiring harness between PJB and ambient temperature sensor

POSSIBLE CAUSE

• Open circuit in wiring harness between PJB terminal J-02 AD and ambient temperature sensor terminal A
• Open circuit in wiring harness between PJB terminal J-02 AF and ambient temperature sensor terminal B
• Short to power supply in wiring harness between PJB terminal J-02 AD and ambient temperature sensor terminal A
• Short to GND in wiring harness between PJB terminal J-02 AD and ambient temperature sensor terminal A
• Ambient temperature sensor circuit short each other
• Ambient temperature sensor malfunction
• PJB malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1

INSPECT AMBIENT TEMPERATURE SENSOR CONNECTOR
• Turn the ignition switch off.
• Disconnect the ambient temperature sensor connector.
• Inspect the ambient temperature sensor connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 8.

No | Go to the next step.
2 | INSPECT PJB CONNECTOR • Disconnect the PJB connector. • Inspect the PJB connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion). • Is there any malfunction? | Yes | Repair or replace the terminal, then go to Step 8.
No | Go to the next step.

3

INSPECT AMBIENT TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT
• Inspect for continuity between following terminals:

  - PJB terminal J-02 AD (wiring harness-side) - ambient temperature sensor terminal A (wiring harness-side)
  - PJB terminal J-02 AF (wiring harness-side) - ambient temperature sensor terminal B (wiring harness-side)

• Is there continuity?

Yes

Go to the next step.

No | Repair or replace the wiring harness for a possible open circuit, then go to Step 8.
4 | INSPECT AMBIENT TEMPERATURE SENSOR SIGNAL CIRCUIT FOR SHORT TO GND • Inspect for continuity between PJB terminal J-02 AD (wiring harness-side) and body GND. • Is there continuity? | Yes | Repair or replace the wiring harness for a possible short to GND, then go to Step 8.
No | Go to the next step.
5 | INSPECT AMBIENT TEMPERATURE SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between PJB terminal J-02 AD (wiring harness-side) and body GND. • Is the voltage B+? | Yes | Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
No | Go to the next step.
6 | INSPECT AMBIENT TEMPERATURE SENSOR CIRCUIT FOR SHORT EACH OTHER • Turn the ignition switch to the LOCK position. • Inspect for continuity between ambient temperature sensor terminals A and B (wiring harness-side). • Is there continuity? | Yes | Repair or replace the wiring harness for a possible short each other, then go to Step 8.
No | Go to the next step.
7 | INSPECT AMBIENT TEMPERATURE SENSOR • Inspect the ambient temperature sensor. (See AMBIENT TEMPERATURE SENSOR INSPECTION.) • Is there any malfunction? | Yes | Replace the ambient temperature sensor, then go to the next step. (See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION.)
No | Go to the next step.

8

VERIFY TROUBLESHOOTING COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PJB memory using the WDS or equivalent.
• Perform the self-test.
(See PJB SELF-TEST.)
• Is the same DTC present?

Yes

Replace the PJB.
(See PASSENGER JUNCTION BOX (PJB) REMOVAL/INSTALLATION.)

No | Troubleshooting completed.