Component Tests and General Diagnostics

Voltage Supply For Engine Control Module (ECM), Checking

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

Test requirements







- 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 defroster must be switched off.
- Parking brake must be engaged or else day time driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- For vehicles with automatic transmission, selector lever must be in -P-.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.

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 at terminal 30
- Measure voltage supply between sockets 1 + 62 and 2 + 62 of test box.

Specified value: at least 11.5V

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.

Checking voltage supply at terminal 15

Vehicles with engine code APH, AWP, AWV
- Measure voltage supply between sockets 1+3 and 2 + 3 of test box.

Vehicles with engine code BKF, BNU
- Measure voltage supply between sockets 1+21 and 2 + 21 of test box.

Continue for all vehicles
- Switch ignition on.

Specified value: at least 11.5V

- Switch ignition off.

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