DTC P0072:00 [PCM (SKYACTIV-G 2.5T)]

id0102s8145900

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 0.14 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 is not available.
•  Snapshot data is 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 2Q
•  PCM connector or terminals malfunction
•  Ambient temperature sensor signal circuit and ground circuit are shorted to each other
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the snapshot data on the repair order.
—
Go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT AMBIENT TEMPERATURE SENSOR CONNECTOR CONDITION
•  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 9.
No
Go to the next step.
4
DETERMINE IF AMBIENT TEMPERATURE SENSOR OR WIRING HARNESS MALFUNCTION
•  Verify that the ambient temperature sensor connector is disconnected.
•  Switch the ignition ON (engine off).
Note
•  Another DTC may be stored by the PCM detecting an open circuit.
•  Measure the voltage at the ambient temperature sensor terminal A (wiring harness-side).
•  Is the voltage approx. 5 V?
Yes
Replace the ambient temperature sensor, then go to Step 9.
(See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION.)
No
Go to the next step.
5
INSPECT AMBIENT TEMPERATURE SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Verify that the ambient temperature sensor connector is disconnected.
•  Switch the ignition off.
•  Inspect for continuity between ambient temperature sensor terminal A (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Disconnect the PCM connector and inspect the wiring harness for short to ground.
•  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 2Q.
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).
Go to Step 9.
No
Go to the next step.
6
INSPECT PCM CONNECTOR CONDITION
•  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 9.
No
Go to the next step.
7
INSPECT AMBIENT TEMPERATURE SENSOR SIGNAL CIRCUIT AND GROUND CIRCUIT FOR SHORT TO EACH OTHER
•  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 2Q
•  Ambient temperature sensor terminal B—PCM terminal 2V
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 Step 9.
No
Go to the next step.
8
INSPECT AMBIENT TEMPERATURE SENSOR
•  Inspect the ambient temperature sensor.
•  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.
9
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOEO or KOER self test.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
DTC troubleshooting completed.