Pump-Injector Unit, Checking

Pump-Injector Unit, 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

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

Test sequence
- Disconnect 8-pin connector for Pump-Injector Units on cylinder head.
- Check resistance of Pump-Injector Unit valves between connector terminals of connector (connector to Pump-Injector Units).

Cyl. 1: Terminals 7 + 5
Cyl. 2: Terminals 7 + 3
Cyl. 3: Terminals 7 + 2
Cyl. 4: Terminals 7 + 6

Specified value: 0.1 to 1.0 Ohms

- Check wires for short circuit to each other as well as to vehicle Ground (GND).
Specified value: Infinite Ohms

If specified value is obtained:
- Check wires to Engine Control Module (ECM) according to wiring diagram.

If specified value is not obtained:
- Remove upper toothed belt guard and cylinder head cover.
- Pry off connectors of all 4 pump-injector units using a screwdriver. In order to avoid canting, support opposite side of connector with light finger pressure.







- Check resistance of Pump-Injector Unit valves between connector terminals at Pump-Injector Unit valves.
Specified value: 0.1 to 1.0 Ohms

If specified value is not obtained:
- Replace malfunctioning Pump-Injector Unit, removing and installing Pump-Injector Unit.
- 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 specified value is obtained:
- Check wires between harness connector for Pump-Injector Unit on cylinder head and all 4 connectors (terminal 1) for open circuit.

Cyl. 1: Terminal 1 + terminal 5
Cyl. 2: Terminal 1 + terminal 3
Cyl. 3: Terminal 1 + terminal 2
Cyl. 4: Terminal 1 + terminal 6

Wire resistance: max. 1.5 Ohms

- Check wires between harness connector for Pump-Injector Unit on cylinder head and all 4 connectors (terminal 2) for open circuit.

Terminal 2 + terminal 7

Wire resistance: max. 1.5 Ohms

- Check wires for short circuit to each other.
Specified value: Infinite Ohms

Check wires to control module
- Connect test box (1598/42) to Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248- wiring harness using adapter cable (V.A.G 1598/39-1), connecting test box for wiring test. Test Box, Connecting For Wiring Test
- Check wires between test box and 8-pin connector to for open circuit according to wiring diagram (connector to Engine Control Module -ECM-).

Terminal 2 + socket 47
Terminal 3 + socket 1
Terminal 5 + socket 46
Terminal 6 + socket 48
Terminal 7 + socket 31

Wire resistance: max. 1.5 Ohms

- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinite Ohms

If no malfunctions are found in wires:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-.