#
DTC P0380 [MZR-CD (RF Turbo)]

BME010200300W12

DTC P0380 | Glow plug relay circuit malfunction
--- | ---
DETECTION CONDITION | • PCM monitors input voltage from glow plug relay while engine is running. PCM determines glow plug relay circuit malfunction if input voltage from glow plug relay is as following: - 1.0 V or below when glow plug relay is on. - 4.0 V or above when glow plug relay is off.
POSSIBLE CAUSE | • Glow plug relay malfunction • Connector or terminal malfunction • Short to GND in wiring between glow plug relay terminal D and PCM terminal 68 • Short to GND in wiring between glow plug fuse and glow plug relay terminal A • Short to GND in wiring between glow plug relay terminal C and PCM terminal 86
• Short to power circuit in wiring between glow plug relay terminal D and PCM terminal 68
• Short to power circuit in wiring between glow plug relay terminal C and PCM terminal 86
• Glow plug relay power and signal circuits short each other
• Open circuit in wiring between glow plug fuse and glow plug relay terminal A
• Open circuit in wiring between glow plug relay terminal B and GND
• Open circuit in wiring between glow plug relay terminal D and PCM terminal 68
• Open circuit in wiring between glow plug relay terminal C and PCM terminal 86
• PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Check for related Service Information availability. • Is any related repair information available? | Yes | Perform repair or diagnosis according to available Service Information. • If vehicle is not repaired, go to next step.
No | Go to next step.
2 | INSPECT POOR CONNECTION OF GLOW PLUG RELAY CONNECTOR • Turn engine switch to OFF. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace suspected terminal, go to Step 9.
No | Go to next step.
3 | INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT TO GND • Turn engine switch to OFF. • Inspect continuity between following harnesses:

  - Glow plug relay terminal A and body GND.
  - Glow plug relay terminal C and body GND.
  - Glow plug relay terminal D and body GND.

• Is there continuity?
Yes
Repair or replace harness for short to GND, go to Step 9.
No | Go to next step.
4 | INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT TO POWER • Turn engine switch to ON (Engine OFF). • Inspect voltage between following harnesses:

  - Glow plug relay terminal C and body GND.
  - Glow plug relay terminal D and body GND.

• Is voltage below 1.0 V?
Yes
Go to next step.
No | Repair or replace harness for short to power, go to Step 9.
5 | INSPECT GLOW PLUG RELAY CIRCUIT FOR SHORT WITH EACH OTHER • Turn engine switch to OFF. • Inspect continuity between glow plug relay terminals A and C. • Is there continuity? | Yes | Repair or replace harness for short with each other, go to Step 7.
No | Go to next step.
6 | INSPECT GLOW PLUG RELAY CIRCUIT FOR OPEN • Turn engine switch to OFF. • Inspect continuity between following harnesses:

  - Glow plug fuse and glow plug relay terminal A.
  - Glow plug relay terminal B and body GND.

• Is there continuity?
Yes
Go to next step.
No | Repair or replace harness for open, go to Step 9.
7 | INSPECT GLOW PLUG RELAY • Inspect glow plug relay. (See RELAY INSPECTION.) • Is there any malfunction? | Yes | Replace glow plug relay, go to Step 9.
No | Go to next step.
8 | INSPECT POOR CONNECTION OF PCM CONNECTOR • Turn engine switch to OFF. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace suspected terminal, go to Step 9.
No | Go to next step.
9 | INSPECT GLOW PLUG RELAY CIRCUIT FOR OPEN • Turn engine switch to OFF. • Inspect continuity between following harnesses:

  - Glow plug relay terminal D and PCM terminal 68.
  - Glow plug relay terminal C and PCM terminal 86.

• Is there continuity?
Yes
Go to next step.
No | Repair or replace harness for open, go to next step.
10 | VERIFY TROUBLESHOOTING OF DTC P0380 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear DTC from PCM memory using WDS or equivalent. • Start engine. • Is same DTC present? | Yes | Replace PCM, go to next step. (See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
No | Go to next step.
11 | VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [MZR-CD (RF Turbo)].) • Is there any DTC present? | Yes | Go to applicable DTC inspection. (See DTC TABLE [MZR-CD (RF Turbo)].)
No | Troubleshooting completed.