Mazda Factory OBD-II DTC P0112 Code

DTC P0112 Intake air temperature (IAT) sensor circuit low input
DETECTION CONDITION
•  The PCM monitors the IAT sensor signal. If the voltage at PCM terminal 231 remains low, the PCM determines that there is an IAT sensor circuit problem.
POSSIBLE CAUSE
•  IAT sensor malfunction
•  Connector or terminal malfunction
•  Short to ground in the wiring harness between IAT sensor terminal F and PCM terminal 231
•  PCM malfunction

Diagnostic procedure

STEP INSPECTION ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
•  Verify related service 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.
3
VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT?
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists.
Perform the “INTERMITTENT CONCERNS TROUBLESHOOTING”.
4
CLASSIFY MALFUNCTION AS IAT SENSOR OR IAT SENSOR SIGNAL CIRCUIT MALFUNCTION
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between IAT sensor terminal F (wiring harness-side) and body ground.
•  Verify that the voltage while disconnect the IAT sensor connector.
•  Does the IAT sensor voltage change from Below 1.0 V to 5.0 V?
Yes
Go to Step 7.
No
Go to the next step.
5
INSPECT IAT SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Inspect for continuity between PCM terminal 231(wiring harness-side) and body ground.
•  Is there continuity?
Yes
Repair or replace the wiring harness between IAT sensor terminal F (wiring harness-side) and PCM terminal 231 (wiring harness-side), then go to Step 9.
No
Go to the next step.
6
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine 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 terminal, then go to Step 9.
No
Go to Step 9.
7
INSPECT IAT SENSOR CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the IAT sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
8
INSPECT IAT SENSOR
•  Inspect the IAT sensor.
•  Is there any malfunction?
Yes
Replace the MAF/IAT sensor, then go to the next step.
No
Go to the next step.
9
VERIFY THAT DTC P0112 TROUBLESHOOTING IS COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Replace the PCM, then 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.
No
DTC troubleshooting completed.

 

 

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