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:
| Rapid data transfer HELP Select function XX |
- Press buttons - 0 - and - 3 - for "Output Diagnostic Test Mode" and confirm with - Q - button.
Indicated on display:
| Rapid data transfer Q 03 Output Diagnostic Test Mode |
- Confirm input with - Q - button.
Indicated on display:
| Output Diagnostic Test Mode -> Commencement of injection valve N108 |
- Press → button.
Indicated on display:
| Output Diagnostic Test Mode -> Exhaust gas recirculation valve N18 |
- Press → button.
Indicated on display:
| Output Diagnostic Test Mode -> A/C compressor interrupt |
- 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
- 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 .