DTC P0538:00 [MZR 1.3, MZR 1.5]

id0102f8705300

DTC P0538:00

Evaporator temperature sensor circuit high input
DETECTION CONDITION
•  If the input voltage is 4.9 V or more for 16 s or more, the PCM determines that the evaporator temperature sensor circuit has a malfunction.
Diagnostic support note
•  This is a continuous monitor (other).
•  The MIL does not illuminate.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Evaporator temperature sensor connector or terminals malfunction
•  Evaporator temperature sensor malfunction
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between evaporator temperature sensor terminal B and PCM terminal 1AW
•  Open circuit in wiring harness between the following terminals:
―  Evaporator temperature sensor terminal B—PCM terminal 1AW
―  Evaporator temperature sensor terminal A—PCM terminal 1AG
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
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.
2
INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR CONDITION
•  Turn the ignition switch off.
•  Disconnect the evaporator 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
CLASSIFY EVAPORATOR TEMPERATURE SENSOR MALFUNCTION OR WIRING HARNESS MALFUNCTION
•  Evaporator temperature sensor connector is disconnected.
•  Access the A/CT V PID using the M-MDS.
•  Connect a jumper wire between evaporator temperature sensor terminals B and A (wiring harness-side).
•  Verify the A/CT V PID value.
•  Is the voltage less than 4.9 V?
Yes
Inspect the evaporator temperature sensor.
(See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)
•  Replace the evaporator temperature sensor, if necessary.
Go to Step 7.
No
Go to the next step.
4
INSPECT PCM CONNECTOR CONDITION
•  Turn the ignition switch off.
•  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.
5
INSPECT EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Evaporator temperature sensor and PCM connectors are disconnected.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage at the evaporator temperature sensor terminal B (wiring harness-side).
•  Is there any voltage?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 7.
No
Go to the next step.
6
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Evaporator temperature sensor and PCM connectors are disconnected.
•  Turn the ignition switch off.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Evaporator temperature sensor terminal B—PCM terminal 1AW
―  Evaporator temperature sensor terminal A—PCM terminal 1AG
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
7
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to 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.
8
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.3, MZR 1.5].)
No
DTC troubleshooting completed.