Component Tests and General Diagnostics

Voltage Supply For Engine Control Module (ECM), Checking

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







- The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK
- Fuel Pump (FP) Relay -J17- must be OK, check
- Generator (GEN) must be OK, checking:
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as, lights and rear window heating must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.

Test sequence
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Checking voltage supply terminal 30

Vehicles with engine code AEB
- Measure voltage supply between sockets 2 + 3 of test box.
Specified value: at least 11.5 V

Vehicles with engine code ATW, AUG, AWM
- Measure voltage supply between sockets 1 + 62 and 2 + 62 of test box.
Specified value: at least 11.5 V

Continued for all vehicles
If specified value is not obtained:
- Check wire connections to relay carrier and Ground (GND) connection of Engine Control Module (ECM) according to wiring diagram
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

Checking voltage supply terminal 15

Vehicles with engine code AEB
- Measure voltage supply between sockets 1 + 2 of test box.

Vehicles with engine code ATW, AUG, AWM
- Measure voltage supply between sockets 1 + 3 and 2 + 3 of test box.

Continued for all vehicles
- Switch ignition on.
Specified value: at least 11.5 V
If specified value is not obtained:
- Check wire connections to relay carrier and Ground (GND) connection of Engine Control Module (ECM) according to wiring diagram
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes