Turbo Boost Sensor: Testing and Inspection

Charge Air Pressure Sensor, Checking

NOTE: Use only gold-plated terminals when servicing terminals in harness connector.

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1397 A Turbocharger tester
- 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.
- If vehicle is equipped with an A/C system, it must be switched off.
- For vehicles with automatic transmission, selector lever must be in position -P- or -N-.
- Parking brake must be engaged.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition is switched off.

Function test
- Connect diagnostic tester. Diagnostic Tester, Connecting
- Switch ignition on.
- Under address word 33, select "Diagnostic mode 1: Check measured values."
- Select the measuring value "PID 11: Manifold Absolute Pressure (MAP)".
- Compare Manifold Absolute Pressure (MAP) displayed on the diagnostic tester and the display on turbocharger tester V.A.G 1397/A with each other.
Specified value: The pressures must match (Tolerance ± 50 mbar or 5 kPaA)

NOTE:
- The turbocharger tester is required to obtain an independent comparison value. Turbocharger tester must be set to measuring range I (absolute pressure). A barometer can be used in its place.
- Manifold Absolute Pressure (MAP) is displayed in kPaA on the diagnostic tester, in mbar on the turbocharger tester Conversion: 1 mbar = 0.1 kPaA.

If specified value is not obtained:
- End diagnosis and switch ignition off.
- Check wires to Engine Control Module (ECM) according to wiring diagram.

Check wires to control module







- Disconnect connector from Charge Air Pressure Sensor -G31- with Intake Air Temperature (IAT) Sensor -G42- (arrow).
- Connect test box (1598/42) to Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248- wiring harness using adapter cable (V.A.G 1598/39-2), connecting test box for wiring test. Test Box, Connecting For Wiring Test







- Check wires between test box and connector for open circuit according to wiring diagram.

Terminal 3 + socket 62
Terminal 4 + socket 78

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 Charge Air Pressure Sensor -G31- with Intake Air Temperature (IAT) Sensor -G42-.
- 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