| Mazda P138A | Glow plug relay system voltage |
|---|---|
|
DETECTION CONDITION
|
• The PCM monitors the input voltage from the glow plug relay signal. If the voltages at PCM terminal 210 deviates from the threshold, the PCM determines that the there is a glow plug relay range/performance malfunction.
|
|
POSSIBLE CAUSE
|
• Glow plug relay malfunction
• PCM malfunction
• Connector or terminal malfunction
• Open circuit in the wiring harness between Glow plug relay terminal C and PCM terminal 210
• Short to ground in the wiring harness between Glow plug relay terminal C and PCM terminal 210
• Short to power supply in the wiring harness between Glow plug relay terminal C and PCM terminal 210
|
 |
|
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 off.
• 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 10.
|
|
No
|
Go to the next step.
|
||
|
5
|
INSPECT GLOW PLUG RELAY CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
• Turn the engine switch to the ON position.
• Remove the glow plug relay.
• Measure the voltage between glow plug relay terminal C and body ground.
• Is the voltage B+?
|
Yes
|
Repair or replace the wiring harness for a short to power supply, then go to Step 10.
|
|
No
|
Go to the next step.
|
||
|
6
|
INSPECT GLOW PLUG RELAY
• Inspect glow plug relay.
• Is there any malfunction?
|
Yes
|
Replace glow plug relay, then go to Step 10.
|
|
No
|
Go to the next step.
|
||
|
7
|
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 10.
|
|
No
|
Go to the next step.
|
||
|
8
|
INSPECT GLOW PLUG RELAY CONTROL CIRCUIT FOR SHORT TO GROUND
• Turn the engine switch off.
• Inspect for continuity between glow plug relay terminal C and body ground.
• Is there continuity?
|
Yes
|
Repair or replace the wiring harness for a short to ground, then go to Step 10.
|
|
No
|
Go to the next step.
|
||
|
9
|
INSPECT GLOW PLUG RELAY SIGNAL CIRCUIT FOR OPEN CIRCUIT
• Turn the engine switch off.
• Inspect for continuity between glow plug relay terminal C and PCM terminal 210.
• 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.
|
||
|
10
|
VERIFY THAT DTC P138A 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.
|
||
|
11
|
VERIFY AFTER REPAIR PROCEDURE
• Perform the after repair procedure.
• Are any DTCs present?
|
Yes
|
Go to the applicable DTC inspection.
|
|
No
|
DTC troubleshooting completed.
|
||