Inspection Procedure 23: Glow System

OPERATION

The engine-ECU controls the glow plug relay and glow indicator lamp based on the signal of the engine coolant temperature sensor in order to easily start the engine at the cool condition.

PROBABLE CAUSES

Failed glow control relay
Failed glow plug
Damaged harness (Open or short circuit between engine-ECU and glow plug relay, and open or short circuit between glow plug relay and glow plug, Open circuit between engine control relay and glow plug relay, engine control relay and fusible link, and open circuit between engine-ECU and combination meter)
Damaged connector (Engine-ECU connector, glow plug relay connector, combination meter connector)
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the glow indicator lamp illuminates.

Ignition switch: ON
Engine coolant temperature: 40°C or lower

Q. Is the glow indicator lamp illuminates?

	Go to Step 4 .

	Go to Step 2 .

STEP 2. Connector check: C-105 engine-ECU connector and C-111 combination meter connector.

Q. Are the check results normal?

Go to Step 3 .

Repair or replace.

STEP 3. Perform voltage measurement at C-105 engine-ECU connector.

Disconnect connector, and measurement at harness side.
Ignition switch: ON
Voltage between terminal No. 28 and earth.

OK: System voltage

Q. Is the check result normal?

Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing

). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns

Check intermediate connector C-53 <L.H. drive vehicles> or C-35 <R.H. drive vehicles>, and repair if necessary. If intermediate connector is normal, check and repair harness between C-111 (terminal No. 51) combination meter connector and C-105 (terminal No. 28) engine-ECU connector.

STEP 4. Connector check: A-11, A-111 and A-112 glow plug relay connectors.

Q. Are the check results normal?

Go to Step 5 .

Repair or replace.

STEP 5. Check the glow plug relay itself.

Check the glow plug relay itself (Refer to GROUP 16 - Glow System - On-vehicle Service - Glow Plug Relay Check ).

Q. Is the check result normal?

	Go to Step 6 .

	Replace the glow plug relay.

STEP 6. Perform voltage measurement at A-11 glow plug relay connector.

Disconnect connector, and measurement at harness side.
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 7 .

Check harness between fusible link No. 24 and A-11 (terminal No. 1) glow plug relay connector.

STEP 7. Perform voltage measurement at A-112 glow plug relay connector.

Disconnect connector, and measurement at harness side.
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 8 .

Check harness between A-112 (terminal No. 1) glow plug relay connector and A-20X (terminal No. 3) engine control relay connector.

STEP 8. Check glow plug itself.

Check glow plug itself (Refer to GROUP 16 - Glow System - On-vehicle Service - Glow Plug Check ).

Q. Is the check result normal?

	Go to Step 9 .

	Replace glow plug.

STEP 9. Check harness between A-111 (terminal No. 1) glow plug relay connector and A-06 (terminal No. 1) glow plug connector.

Q. Is the check result normal?

Go to Step 10 .

Repair the harness wire.

STEP 10. Connector check: C-105 engine-ECU connector.

Q. Is the check result normal?

Go to Step 11 .

Repair or replace.

STEP 11. Check harness between A-112 (terminal No. 2) glow plug relay connector and C-105 (terminal No. 29) engine-ECU connector.

Q. Is the check result normal?

Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing

). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns

Repair the harness wire.