Test sequence

• Connect Scan Tool VAG1551 ( VAG1552 ) and select engine electronics control unit with the "Engine electronics" address word 01. When doing this the engine must be running at idling speed. (Connecting Scan Tool and selecting engine electronics control unit → Scan Tool VAG1551 , connecting  .)

Indicated on display:

• Press buttons 0 and 8 for the function "Read measured value block" and confirm entry with Q button.

Indicated on display:

• Press buttons 0 , 0 and 7 for "Display group number 7" and confirm entry with Q button.

Indicated on display:

• If no realistic display appears in display field 3 or a substitute temperature of 136.8 ° C is displayed, check intake manifold temperature sensor and the wiring to the sensor as follows:
• Press → button.
• Press buttons 0 and 6 for the function "End output" and confirm entry with the Q button.
• Switch off ignition.

• Remove the right headlight: → 94 LIGHTS, SWITCHES - EXTERIOR
• Disconnect 4-pin connector from MAP sensor G71 with Intake Air Temperature (IAT) Sensor G72 - arrow  -. Fitting location overview.

Fig 1: 4-Pin Sensor Connector & Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Measure resistance between sensor contacts 1+2.

Fig 2: Resistance Values Graph

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Specification see diagram

Scale A shows resistance values for temperature range 0 to 50 ° C and scale B the values for temperature range 50 to 100 ° C.

Examples:

• 30 ° C corresponds to a resistance from 1500 to 2000 Ω
• 80 ° C corresponds to a resistance from 275 to 375 Ω

If specification is not obtained:

• Replace intake manifold pressure sensor G71 together with intake manifold temperature sensor G72.
• Check DTC memory and, if necessary, repair any malfunctions and then erase → Diagnostic Trouble Code (DTC) memory, checking and erasing  .
• If the DTC memory has been erased, the readiness code must be generated again → Readiness code, setting  .

If the specification is obtained:

• Remove wiper arms and plenum cover: → 92 WINDSHIELD WIPER & WASHER SYSTEM

Fig 3: Identifying Test Box V.A.G 1598/31 Connected To Control Module Wiring Harness

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Connect test box VAG1598/31 to control unit wiring harness.

Fig 4: Identifying Connector Terminals 1 And 4

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Check wiring between test box and connector for open circuit using wiring diagram.

Contact 1+ socket 52

Contact 2+ socket 73

Wire resistance: max. 1.5 Ω

• Check wires for short to one another, to vehicle Ground and to battery positive (B+).

Specification: ∞Ω

If no fault is detected in the wiring:

• Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 → Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 , replacing  .