Mazda Factory OBD-II DTC P0238 Code Diagnostic Procedure

P0238 Manifold absolute pressure (MAP) sensor circuit high input
DETECTION CONDITION
•  The PCM monitors the MAP sensor signal. If the voltage at PCM terminal 234 remains high, the PCM determines that there is an MAP sensor circuit problem.
POSSIBLE CAUSE
•  MAP sensor malfunction
•  Connector or terminal malfunction
•  Short to power supply in the wiring harness between MAP sensor terminal A and PCM terminal 234
•  Open circuit in the wiring harness between MAP sensor terminal B and PCM terminal 204
•  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 MAP SENSOR POWER CIRCUIT FOR SHORT TO POWER SUPPLY OR OTHER MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the MAP sensor connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between MAP sensor terminal C (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Go to the next step.
No
Go to Step 7.
5
INSPECT MAP SENSOR POWER CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch off.
•  Disconnect the MAP sensor connector and the PCM connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between PCM terminal 205 (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Repair or replace the wiring harness between MAP sensor terminal C (wiring harness-side) and PCM terminal 205 (wiring harness-side), then go to Step 15.
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 15.
No
Go to Step 15.
7
CLASSIFY MALFUNCTION AS MAP SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY OR OTHER MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the MAP sensor connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between MAP sensor terminal A (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Go to the next step.
No
Go to Step 10.
8
CLASSIFY MALFUNCTION AS MAP SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY OR INSTRUMENT CLUSTER MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the MAP sensor connector and the PCM connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between PCM terminal 234 (wiring harness-side) and body ground.
•  Is the voltage more than 5V?
Yes
Repair or replace the wiring harness between MAP sensor terminal A (wiring harness-side) and PCM terminal 234 (wiring harness-side), then go to Step 15.
No
Go to the next step.
9
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 15.
No
Go to Step 15.
10
CLASSIFY MALFUNCTION AS MAP SENSOR GROUND CIRCUIT FOR OPEN OR MAP SENSOR MALFUNCTION
•  Turn the engine switch off.
•  Inspect for continuity between MAP sensor terminal B (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Go to Step 13.
No
Go to the next step.
11
INSPECT MAP SENSOR GROUND CIRCUIT FOR OPEN
•  Turn the engine switch off.
•  Inspect for continuity between PCM terminal 204 (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Repair or replace the wiring harness between MAP sensor terminal B (wiring harness-side) and PCM terminal 204 (wiring harness-side), then go to Step 15.
No
Go to the next step.
12
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 15.
No
Go to Step 15.
13
INSPECT MAP SENSOR CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the MAP 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 15.
No
Go to the next step.
14
INSPECT MAP SENSOR
•  Inspect the MAP sensor.
•  Is there any malfunction?
Yes
Replace the MAP sensor, then go to the next step.
No
Go to the next step.
15
VERIFY THAT DTC P0238 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.
16
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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