DTC P1378:00 [MZR-CD 2.2]

id0102f3149300

DTC P1378:00

Fuel injector supply voltages circuit low input
DETECTION CONDITION
•  The PCM monitors the supply voltage to the fuel injector. If the fuel injector supply voltage is less than 52.4 V when the ignition switch is on, the PCM determines that there is a malfunction in the fuel injector circuit.
Monitoring conditions
―  Following conditions are met:
•  Battery voltage: more than 8 V
•  Time from switch the ignition to on: 2 sec.
Diagnostic support note
•  The MIL illuminates if the PCM detects the above malfunction condition in first drive cycle.
•  PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Fuel injector connector or terminal malfunction
•  Short to ground in the wiring harness between the fuel injector No.1 terminal A and PCM terminal 1D
•  Short to ground in the wiring harness between the fuel injector No.2 terminal A and PCM terminal 1A
•  Short to ground in the wiring harness between the fuel injector No.3 terminal A and PCM terminal 1B
•  Short to ground in the wiring harness between the fuel injector No.4 terminal A and PCM terminal 1C
•  Fuel injector malfunction
•  PCM connector or terminal malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has 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 SERVICE INFORMATION
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
•  If 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.
•  Start the engine.
•  Is the PENDING CODE for this DTC present?
Yes
Go to the next step.
No
Intermittent concern exists.
Perform the “INTERMITTENT CONCERN TROUBLESHOOTING”.
(See INTERMITTENT CONCERN TROUBLESHOOTING [MZR-CD 2.2].)
4
INSPECT FUEL INJECTOR CONNECTOR FOR POOR CONNECTION
•  Switch the ignition to ON.
•  Inspect for poor connection. (such as damaged/pulled-out terminals, corrosion).
•  Is there any malfunction?
Yes
Go to the next step.
No
Repair or replace the terminal, then go to Step 8.
5
INSPECT FUEL INJECTORS CIRCUIT FOR SHORT TO GROUND
•  Switch the ignition to off.
•  Inspect for continuity between the following terminals and body ground:
―  Fuel injector No.1 terminal A
―  Fuel injector No.2 terminal A
―  Fuel injector No.3 terminal A
―  Fuel injector No.4 terminal A
•  Is there continuity?
Yes
Repair or replace the wiring harness for a short to ground, then go to Step 8.
No
Go to the next step.
6
INSPECT FUEL INJECTOR
•  Inspect the fuel injector.
•  Is there any malfunction?
Yes
Replace the fuel injector, then go to Step 8.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR-CD 2.2].)
No
Go to the next step.
7
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Switch the ignition to off.
•  Inspect for poor connection. (such as damaged/pulled-out terminals, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to the next step.
No
Go to the next step.
8
VERIFY TROUBLESHOOTING OF DTC P1378:00 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR-CD 2.2].)
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the "AFTER REPAIR PROCEDURE".
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR-CD 2.2])
No
Troubleshooting completed.