Test sequence

• Connect VAG1551 /1552 (Connecting scan tool and selecting engine electronics control module → Scan Tool VAG1551 , connecting  .) Run engine at idle speed and press buttons 0 and 1 to select "Engine electronics" address word 01.

Indicated on display:

Rapid data transfer HELP Select function XX

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

Indicated on display:

Read measured value block Enter display group number XXX

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

• Indicated on display:

  Read measured value block 7 → 15.4 ° C 15.9 ° C 16.7 ° C

• Observe coolant temperature figure in display field 4. The temperature figure must increase uniformly and without interruption.
• In case of faults the fuel temperature is displayed as a substitute.
• If no realistic display appears in display field 4 or the fuel temperature is displayed as a substitute. Check coolant temperature sensor and wiring connections to sensor as follows:

• Press the → button.
• Press buttons 0 and 6 for the function "End output" and confirm entry with the Q button.
• Switch off ignition.

• Disconnect the connector from coolant temperature sensor.
• Measure resistance between sender contacts C - 1  - +D - 3  -.

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 ECT Sensor G62.
• Check DTC memory and, if necessary, repair any malfunctions and then erase → Diagnostic Trouble Code (DTC) memory, checking and erasing  .
• Read-out the readiness code → Reading readiness code  . If the DTC memory has been erased, the readiness code must be generated again → Readiness code, setting  .

If specification is obtained:

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

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

• Check wiring between test box and 4-pin connector for open circuit using wiring diagram.

Terminal 3+ socket 112

Terminal 4+ socket 104

Wire resistance: max. 1.5 Ω

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

Specification: ∞Ω

• If wiring and the resistance measurement values are OK, replace Diesel Direct Fuel Injection Engine Control Module J248 → Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 , replacing  .