Automatic Glow Time Control Module - J179- And Glow Plug, Checking
General Description
The glow plugs are activated by the Engine Control Module -J623- through the Automatic Glow Time Control Module -J179-. The voltage on the individual glow plugs is adjusted over the frequency of the PWM impulses. For quick start with an ambient temperature of less than 64° F (18° C), a maximum voltage of 11.5 volts is present during preheating. This ensures that the glow plug heats up as quickly as possible (maximum two seconds) to over 1, 832° F (1, 000° C), thus reducing the preheating time of the engine. Post-heating is performed up to a coolant temperature of 64° F (18° C) after engine start for a maximum of five minutes. Post-heating helps reduce hydrocarbon emissions and combustion noise during the engine warm-up phase.
Special Tools And Workshop Equipment Required
- Multimeter.
- Wiring Diagram.
- Scan Tool.
Test Requirements
- Fuses OK.
- Battery voltage OK.
- Switch OFF all electrical and electronic accessories.
- Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
- Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
- Coolant Temperature: < 18° C.
- Observe all safety precautions, refer to SAFETY PRECAUTIONS
.
- View clean working conditions, refer to CLEAN WORKING CONDITIONS
.
- For Hybrid vehicles refer to, Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS
.
NOTE:
The Glow Plug terminal / connector is not repairable. The harness must be replaced if damaged.
Test Procedure
| Step |
Procedure |
Result / Action to Take |
| 1 |
- PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK
.
-- Was Complaint verified? |
-- YES:
-- NO:
- GATHER more information from customer about the complaint.
|
| 2 |
-- Are There fault codes present for the Glow Plugs -- ? |
-- YES:
-- NO:
|
| 3 |
- IGNITION: OFF.
- DISCONNECT: Automatic Glow Time Control Module -J179- harness connector.
- IGNITION: ON.
- CHECK: Automatic Glow Time Control Module -J179- harness connector terminals 30 and 106(6) to ground for voltage.
- CHECK: Automatic Glow Time Control Module -J179- harness connector terminal 107(7) to Battery voltage for voltage.
- SPECIFIED VALUE: Battery voltage.
- IGNITION: OFF.
-- Were Values obtained? |
-- YES:
-- NO:
- PERFORM: Visual Inspection of wiring and component.
- CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals.
- REPAIR: Faulty wiring or connector.
- REPLACE: Any open Fuses.
- GO TO: Step 7
|
| 4 |
- CHECK: Automatic Glow Time Control Module -J179- harness connector terminal 109(9) to Engine Control Module -J623- harness connector T94 / 24 for resistance.
- CHECK: Automatic Glow Time Control Module -J179- harness connector terminal 110(10) to Engine Control Module -J623- harness connector T94 / 74 for resistance.
- SPECIFIED VALUE: 0.5 [Ω] (+/- 0.3 Ω).
-- Were Values obtained? |
-- YES:
- REPLACE: Automatic Glow Time Control Module -J179-. Refer to appropriate repair information.
- GO TO: Step 7
-- NO:
- PERFORM: Visual Inspection of wiring and component.
- CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals.
- REPAIR: Faulty wiring or connector.
- GO TO: Step 7
|
| 5 |
- IGNITION: OFF.
- DISCONNECT: Automatic Glow Time Control Module -J179- harness connector.
- CHECK: The suspected Glow Plug -- (per DTC stored) component connector terminal 4 to ground for resistance (refer to the appropriate wiring diagram for terminal and connector location).
- SPECIFIED VALUE: 1.3 Ω (+/- 0.3 Ω at about 20° C).
- IGNITION: OFF.
-- Was Value obtained? |
-- YES:
-- NO:
- REPLACE: The Glow Plug --. Refer to appropriate repair information.
- GO TO: Step 7
|
| 6 |
- CHECK: Automatic Glow Time Control Module -J179- harness connector terminal to suspected Glow Plug -- harness connector terminal for resistance (refer to the appropriate wiring diagram for terminal and connector location).
- SPECIFIED VALUE: 0.5 [Ω] (+/- 0.3 Ω).
-- Was Value obtained? |
-- YES:
- REPLACE: Automatic Glow Time Control Module -J179-. Refer to appropriate repair information.
- GO TO: Step 7
-- NO:
- PERFORM: Visual Inspection of wiring and component.
- CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals.
- REPAIR: Faulty wiring or connector.
- GO TO: Step 7
|
| 7 |
- Final Procedure
- Perform a road test to verify repair.
-- Does the original DTC return? |
-- YES:
- CHECK: Engine Control Module -J623- harness connector for any damaged, pushed-out pins.
- REPAIR: As necessary.
- If all electrical connections are OK:
- REPLACE: Engine Control Module -J623-. Refer to appropriate repair information.
- Clear the DTC's. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY
.
- Repair is complete. Generate Readiness Code. Refer to READINESS CODE
.
- Return vehicle to Customer.
-- NO:
- Perform the diagnostic procedure for any DTC's.
- If no DTC's return the repair is complete.
- Return vehicle to customer.
|