With Generic Scan Tool

Change-over Valve For Intake Manifold Flap, Checking

Recommended special tools and equipment
- VAG1390 Hand Vacuum Pump
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Diesel-Direct fuel injection system must be OK:
- Battery voltage must be at least 11.5 Volts.

Checking function
- Start engine, and let run at idle.
- Switch ignition off.
- Observe position lever on change-over valve for intake manifold flap (2nd technician required).
- Intake manifold flap must close after ignition is switched off and open again after approx. 3 seconds.

If the change-over does not occur, the following tests must be performed.
- Check whether the change-over mechanism of intake manifold flap moves easily. To do this, operate the linkage by hand.







- Disconnect vacuum hose from vacuum actuator -1-.
- Connect V.A.G 1390 hand vacuum pump to vacuum actuator.
- Operate hand vacuum pump and check the change-over mechanism for the intake manifold flap for ease of movement and function.
- Check whether the vacuum lines are correctly connected.

If no malfunction is detected at mechanical components:
- Check change-over valve for intake manifold flap.

Test sequence
- Disconnect connector from change-over valve for intake manifold flap.







- Measure resistance between terminals of change-over valve:
Specified value: 25...45 ohms

If specified value is not obtained:
- Replace change-over valve for intake manifold flap.
- 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

If specified value is obtained:







- Set multimeter for voltage measurement and connect it to terminals 1 + 2 at connector disconnected from change-over valve for intake manifold flap.
- Start engine, and let run at idle.
Specified value: at least 4.5 V
- Switch ignition off. The voltage value must
fall to 0.0 Volts after approx. 3 seconds.

If voltage value does not change as described:
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Vehicles with 80-pin control module







- Check for open circuit in wires between test box and connector according to wiring diagram.
Terminal 1 + socket 3
Terminal 2 + socket 2
Terminal 2 + socket 28
Wire resistance: max. 1.5 ohms

Vehicles with 121-pin control module







- Check for open circuit in wires between test box and connector according to wiring diagram.
Terminal 1 + socket 1 and 2
Terminal 2 + socket 81
Wire resistance: max. 1.5 ohms

Continuation for all vehicles
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinite Ohms

If no malfunctions are detected in wires:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes