DTC P0072:00 [SKYACTIV-D 1.5]

id0102q2145900

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 0.13 V for 5 s, the PCM determines that the ambient temperature sensor circuit has a malfunction.
Diagnostic support note
•  This is an intermittent 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 2AG
•  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 8.
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 8.
(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.
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 2AG.
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 8.
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 8.
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 2AG
•  Ambient temperature sensor terminal B—PCM terminal 2AT
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.
8
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.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-D 1.5].)
No
DTC troubleshooting completed.