Mazda Factory OBD-II DTC P0380 Code Diagnostic Procedure

P0380 Glow plug circuit malfunction
DETECTION CONDITION
•  The PCM monitors the input voltage from the glow plug relay signal. If the voltages at PCM deviates from the threshold, the PCM determines that the there is a glow plug relay system problem.
POSSIBLE CAUSE
•  Glow plug relay malfunction
•  Glow plug malfunction
•  Connector or terminal malfunction
•  Open circuit in wiring harness between glow plug relay terminal A and fuse
•  Open circuit in wiring harness between glow plug relay terminal D and PCM terminal 132
•  Open circuit in wiring harness between glow plug relay terminal C and PCM terminal 210
•  Short to ground circuit in wiring harness between glow plug relay terminal D and PCM terminal 132
•  Short to ground circuit in wiring harness between glow plug relay terminal C and PCM terminal 210
•  Short to power supply in wiring harness between glow plug relay terminal D and PCM terminal 132
•  Short to power supply in wiring harness between glow plug relay terminal C and PCM terminal 210
•  Open circuit in wiring harness between glow plug relay terminal D and glow plug terminal A
•  Open circuit in wiring harness between glow plug relay terminal D and glow plug terminal B
•  Open circuit in wiring harness between glow plug relay terminal D and glow plug terminal C
•  Open circuit in wiring harness between glow plug relay terminal D and glow plug terminal D
•  Short to ground circuit in wiring harness between glow plug relay terminal D and glow plug terminal A
•  Short to ground circuit in wiring harness between glow plug relay terminal D and glow plug terminal B
•  Short to ground circuit in wiring harness between glow plug relay terminal D and glow plug terminal C
•  Short to ground circuit in wiring harness between glow plug relay terminal D and glow plug terminal D
•  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
INSPECT GLOW PLUG RELAY CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch on.
•  Disconnect the glow plug relay 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 16.
No
Go to the next step.
5
INSPECT GLOW PLUG RELAY POWER SUPPLY FOR OPEN CIRCUIT
•  Turn the engine switch off.
•  Measure the voltage between glow plug relay terminal A and body ground.
•  Measure the voltage between glow plug relay terminal B and body ground.
•  Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for an open circuit, then go to Step 16.
6
INSPECT GLOW PLUG RELAY
•  Inspect the glow plug relay.
•  Is there any malfunction?
Yes
Go to the next step.
No
Replace the glow plug, then go to Step 16.
7
INSPECT GLOW PLUG CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the suspected terminal, then go to Step 17.
No
Go to the next step.
8
INSPECT GLOW PLUG CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch to the ON position (Engine off).
•  Disconnect the PCM connector.
•  Measure the voltage between the following terminals:
―  Glow plug relay terminal D and ground
•  Is the voltage more than 4.0 V?
Yes
Repair or replace the wiring harness for a short to power supply, then go to Step 16.
No
Go to the next step.
9
INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT TO GROUND
•  Turn the engine switch off.
•  Inspect for continuity between the following terminals:
―  Glow plug relay terminal D and ground
•  Is there continuity?
Yes
Repair or replace the wiring harness for a short to ground, then go to Step 16.
No
Go to the next step.
10
INSPECT GLOW PLUG RELAY CIRCUIT FOR OPEN CIRCUIT
•  Turn the engine switch off.
•  Inspect for continuity between the following terminals:
―  Glow plug relay terminal D and glow plug terminal A
―  Glow plug relay terminal D and glow plug terminal B
―  Glow plug relay terminal D and glow plug terminal C
―  Glow plug relay terminal D and glow plug terminal D
•  Is there continuity?
Yes
Go to the next step
No
Repair or replace the wiring harness for an open circuit, then go to Step 16.
11
INSPECT GLOW PLUG
•  Inspect the glow plug.
•  Is there any malfunction?
Yes
Go to the next step.
No
Replace the glow plug, then go to Step 16.
12
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the suspected terminal, then go to Step 16.
No
Go to the next step.
13
INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch to the ON position (Engine off).
•  Disconnect the PCM connector.
•  Measure the voltage between the following terminals:
―  Glow plug relay terminal C and body ground
―  Glow plug relay terminal D and body ground
•  Is the voltage more than 4.0 V?
Yes
Repair or replace the wiring harness for a short to power supply, then go to Step 16.
No
Go to the next step.
14
INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT TO GROUND
•  Turn the engine switch off.
•  Inspect for continuity between the following terminals:
―  Glow plug relay terminal C and body ground.
―  Glow plug relay terminal D and body ground.
•  Is there continuity?
Yes
Repair or replace the wiring harness for a short to ground, then go to Step 16.
No
Go to the next step.
15
INSPECT GLOW PLUG RELAY CIRCUIT FOR OPEN CIRCUIT
•  Turn the engine switch off.
•  Inspect for continuity between the following terminals:
―  glow plug relay terminal C and PCM terminal 210
―  glow plug relay terminal D and PCM terminal 132
•  Is there continuity?
Yes
Go to the next step
No
Repair or replace the wiring harness for an open circuit, then go to the next step.
16
VERIFY THAT DTC P0380 TROUBLESHOOTING IS COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear DTC from PCM memory using 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.
17
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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