Glow Plug System: Testing and Inspection

Glow Plug System, Checking

Only vehicles with engine code BEW and vehicles with engine code ALH, model year >2001

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Requirements







- The respective fuses of Diesel-Direct fuel injection system must be OK.
- Battery voltage must be at least 11.5 volts.
- Ignition switched off

Test sequence

Vehicles with 80-pin control module







- Disconnect 4-pin connector from Engine Coolant Temperature (ECT) Sensor -G62- with Engine Coolant Temperature (ECT) Sensor -G2- (arrow).

Vehicles with 121-pin control module







- Disconnect connector at coolant temperature sensor.

Vehicles with 154-pin control module







- Disconnect connector at coolant temperature sensor.

Continue for all vehicles

NOTE: By disconnecting the connector from the sensor, a "cold" engine state is simulated and a corresponding glow plug procedure is performed when ignition is switched on.

- Disconnect glow plug connectors from glow plugs.
- Switch on ignition.

Vehicles with engine code ALH
- Connect V.A.G 1526 hand multimeter in succession between glow plug connector cylinder 1 and vehicle Ground (GND) as well as between glow plug connector cylinder 3 and vehicle GND for voltage measurement.

Specified value: Battery voltage for approx. 20 s.

Vehicles with engine code BEW
- Connect V.A.G 1526 portable multimeter in succession between glow plug connectors and vehicle Ground (GND) for voltage measurement.
- Specified value:
- Battery voltage for approx. 20 s.

Continue for all vehicles
- If there is no voltage:
- Eliminate error in wires (see circuit diagram):

- Erase DTC memory of control module for Diesel-Direct fuel injection system. Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

Vehicles with engine code ALH, model year 2002 >

NOTE: Vehicles with engine code ALH, model year 2002 > are equipped with Control module for Glow plug activation control - J370- in which the glow plug activation cannot be perceived visually or acoustically and can only be detected by connecting a current-pick up clamp at wires to the glow plugs.

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter

Requirements







- The respective fuses of Diesel-Direct fuel injection system must be OK.
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as, lights and rear window defroster must be switched off.
- If vehicle is equipped with an A/C system, it must be switched off.
- Engine must be cold

Test sequence

NOTE: Test must be performed within 3 minutes after engine start.

- Start engine and let run at idle.
- Connect V.A.G 1715 multimeter with current probe in succession to wires to glow plugs.
- Specified value on display of V.A.G 1715 at least 6 A.

If specified value is obtained:
- Eliminate error in wires (see circuit diagram).
- Erase DTC memory of control module for Diesel-Direct fuel injection system. Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes