DTC P0072:00

Ambient temperature sensor circuit low input

DETECTION CONDITION

• The PCM monitors the input signal from the ambient temperature sensor. If the voltage from the ambient temperature sensor is below 0.18 V, the PCM determines that the ambient temperature sensor circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (other).

• The check engine light does not illuminate.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

Not applicable

POSSIBLE CAUSE

• Ambient temperature sensor connector or terminals malfunction

• Ambient temperature sensor malfunction

• Short to ground in wiring harness between ambient temperature sensor terminal A and PCM terminal 2I

• PCM connector or terminals malfunction

• Ambient temperature sensor signal circuit and ground circuit are shorted to each other

• PCM malfunction

STEP

INSPECTION

ACTION

1

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

2

• Switch the ignition off.

• Disconnect the ambient temperature sensor connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 7.

No

Go to the next step.

3

• Inspect the ambient temperature sensor.

  (See AMBIENT TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)

  (See AMBIENT TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)

• Is there any malfunction?

Yes

Replace the ambient temperature sensor, then go to Step 7.

(See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)

(See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

No

Go to the next step.

4

• Verify that the ambient temperature sensor connector is disconnected.

• Inspect for continuity between ambient temperature sensor terminal A (wiring harness-side) and body ground.

• Is there continuity?

Yes

If the short to ground circuit could be detected in the wiring harness:

• Refer to the wiring diagram and verify whether or not there is a common connector between ambient temperature sensor terminal A and PCM terminal 2I.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

If the short to ground circuit could not be detected in the wiring harness:

• Replace the PCM (short to ground in the PCM internal circuit).

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to Step 7.

No

Go to the next step.

5

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 7.

No

Go to the next step.

6

• Verify that the ambient temperature sensor and PCM connectors are disconnected.

• Inspect for continuity between ambient temperature sensor terminals A and B (wiring harness-side).

• Is there continuity?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• Ambient temperature sensor terminal A—PCM terminal 2I

• Ambient temperature sensor terminal B—PCM terminal 2AJ

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to each other.

Go to the next step.

No

Go to the next step.

7

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Start the engine and warm it up completely.

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [SKYACTIV-G 2.5].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to the next step.

No

Go to the next step.

8

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.