Test sequence

• Connect Scan Tool VAG1551 ( VAG1552 ) and select engine electronics control unit with the "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 "Read measured value block" and confirm entry with Q button.

Indicated on display:

• Press buttons 0 , 0 and 6 for "Display group number 6" and confirm entry with Q button.
• Perform road test with a 2nd person to observe display.

Observe the valid safety precautions when carrying out a road test → Safety precautions  .

• Observe figure in display field 1.

Specification: approx. road speed

If no speed is indicated:

• Press → button.
• Press buttons 0 and 6 for "End output" and confirm with the Q button.
• Switch off ignition.
• Remove wiper arms and plenum cover: → 92 WINDSHIELD WIPER & WASHER SYSTEM

Fig 1: 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.
• Connect multimeter to measure voltage between test box sockets 4/5+20.
• Switch on ignition.
• Lift vehicle at front left.

• Rotate front wheel and observe the LED in the LED test lamp.

LED must flash

(approx. four times per wheel rotation).

If LED test lamp does not flash:

• Check wiring from engine control unit connector contact 20 to dash panel insert for open/short circuit. → Electrical Wiring Diagrams, Troubleshooting and Component Locations
• Check DTC memory and, if necessary, repair any malfunctions and then erase → Diagnostic Trouble Code (DTC) memory, checking and erasing  .
• Read-out readiness code → Reading readiness code  . If DTC memory has been erased, the readiness code must be generated again → Readiness code, setting  .