Dtc P1391 - Mazda 6 Workshop Manual

Diagnostic procedure
STEP
1 VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
• Has FREEZE FRAME DATA been recorded?
2 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Verify related Service Bulletins and/or on-line
repair information availability.
• Is any related repair information available?
3 VERIFY CURRENT SIGNAL STATUS: IS
CONCERN INTERMITTENT OR CONSTANT?
• Connect the WDS or equivalent to the DLC-2.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Start the engine.
• Is the PENDING CODE for this DTC present?
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME
DATA
• Is DTC P0627 on the FREEZE FRAME DATA?
5 INSPECT FUEL PRESSURE SENSOR
• Inspect the fuel pressure sensor.
• Is the fuel pressure sensor normal?
6 INSPECT SUCTION CONTROL VALVE
• Inspect the suction control valve.
• Is the suction control valve normal?
7 VERIFY FUEL PRESSURE LIMITER
MALFUNCTION
• Replace the common rail.
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC using the WDS or equivalent.
• Start the engine.
• Is the PENDING CODE for this DTC present?
8 VERIFY SUPPLY PUMP MALFUNCTION
• Replace the supply pump.
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC using the WDS or equivalent.
• Start the engine.
• Is the PENDING CODE for this DTC present?
9 VERIFY TROUBLESHOOTING OF DTC P1211
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC using the WDS or equivalent.
• Start the engine.
• Is the PENDING CODE for this DTC present?
10 VERIFY AFTER REPAIR PROCEDURE
• Perform the Repair Verification Drive Mode.
(See F2–39 OBD DRIVE
• Are any DTCs present?
End Of Sie

DTC P1391

DTC P1391 Glow plug circuit low input
• The PCM monitors the output signal to the glow relay when the glow relay is on. If the glow relay voltage is
1.0 V or less when the glow relay is operating, The PCM determines that there is a malfunction in the glow
relay circuit.
DETECTION
Diagnostic support note
CONDITION
• The MIL does not illuminates.
• The DTC is stored in the PCM memory.
F2–170
ON-BOARD DIAGNOSTIC
INSPECTION
MODE.)
Yes Go to the next step.
No Record the FREEZE FRAME DATA on the repair order,
then go to the next step.
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.
Yes Go to the next step.
No Intermittent concern exists.
Perform the "INTERMITTENT CONCERNS
TROUBLESHOOTING".
Yes Go to the next step.
No Go to the troubleshooting procedures for the DTC in the
FREEZE FRAME DATA.
Yes Go to the next step.
No Replace the common rail, then go to Step 9.
Yes Go to the next step.
No Replace the supply pump, then go to Step 9.
Yes Go to the next step.
No This DTC cause is fuel pressure limiter malfunction, then
go to Step 9.
Yes Go to the next step.
No The cause for this DTC is a supply pump malfunction, then
go to the next step.
Yes Replace the PCM, then go to the next step.
No Go to the next step.
Yes Go to the applicable DTC troubleshooting.
(See F2–40 DTC TABLE.)
No Troubleshooting completed.
ACTION
B6E407001300101