A/C system signals, checking: Checking

• Connect Scan Tool V.A.G 1551/1552 → Scan Tool V.A.G 1551 , connecting  .
• Start engine and let idle.
• Press - 0  - and - 1  - buttons to select address word 01: " Engine electronics".

Indicated on display:

• Press buttons - 0  - and - 3  - for "Output Diagnostic Test Mode" and confirm with - Q  - button.

Indicated on display:

• Confirm input with - Q  - button.

Indicated on display:

• Press → button.

Indicated on display:

• Press → button.

Indicated on display:

• A/C compressor shut-off is checked.
• A/C compressor must stop within 5 secs., (visual check) then start approx. every 5 secs. and then stop.

If A/C compressor does not switch off:

• Proceed with function 3: Output DTM, until complete.
• Press buttons - 0  - and - 6  - to select function 06: End output:.
• Press - Q  - button to enter input.
• Switch off ignition.

• Remove wiper arms and cowl panel →92 WINDSHIELD WIPER & WASHER SYSTEM

Fig 1: Identifying Test Box V.A.G 1598/22 Connected To Control Module Wiring Harness

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Connect test box V.A.G 1598/22 (through my 1999) or test box V.A.G 1598/31 (from my 2000) to control module wiring harness.
• Check wiring between following test box sockets and the A/C system for open circuit according to wiring diagram.

• Through MY 1999: 16
• From MY 2000: 29

Wire resistance: Max. 1.5 Ω → Electrical Wiring Diagrams, Troubleshooting and Component Locations

• Check DTC memory, if necessary, repair malfunctions.
• Erase DTC memory → Diagnostic Trouble Code (DTC) memory, checking and erasing 
• Display readiness code → Readiness code, displaying  . If DTC memory has been erased, readiness code must be reset → Readiness code, setting  .