EPC Warning Lamp Functional Check

Electronic Power Control (EPC) Warning Lamp In Instrument Cluster, Checking

Significance of EPC warning lamp
"EPC" is an abbreviation and stands for Electronic Power Control and means "electronic engine load control" (E-gas).







Installation location of EPC warning lamp

If malfunctions are recognized in the EPC system during operation of the engine, the Engine Control Module (ECM) switches on the EPC warning lamp. (These malfunctions are listed in the DTC table). An entry is made in DTC memory at the same time.

Recommended special tools and equipment
- V.A.G1526 multimeter or V.A.G1715 multimeter
- V.A.G1594 connector test kit
- Wiring diagram

Requirement







- The respective fuses of Electronic Power Control (EPC) Warning Lamp -K132- must be OK.

Test sequence
- Switch on ignition:

Warning lamp must light up.

If warning lamp does not light up when ignition is switched on:
- Switch ignition off.
- Check wire from Engine Control Module (ECM) to MIL as follows:
- Connect test box to control module wiring harness. Test Box, Connecting For Wiring Test
- Bridge sockets 1 + 48 of test box with the respective adapter cables.
- Switch on ignition:

Warning lamp must light up.

If warning lamp does not light up:
- Switch ignition off.
- Remove instrument cluster:
- Check wiring connection from Engine Control Module (ECM) to Electronic Power Control (EPC) Warning Lamp -K132- 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

If no malfunctions are detected in wire from Engine Control Module (ECM) to warning lamp:
- Replace Motronic Engine Control Module (ECM) -J220-.

If warning lamp lights up when ignition is switched on:
- Start engine and let run at idle:

Warning lamp must go out after a few seconds.

If warning lamp does not go out:
- Switch ignition off.
- Remove instrument cluster:
- Connect test box to control module wiring harness. Test Box, Connecting For Wiring Test
- Check wire connection between test box socket 48 and instrument cluster for short circuit to Ground (GND) 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

If no malfunctions are detected in wire from Engine Control Module (ECM) to warning lamp:
- Replace Motronic Engine Control Module (ECM) -J220-.