Output Diagnostic Test Mode (Scan Tool Function 03)

- Check DTC memory, eliminate or repair any malfunctions.
- Keep engine running after checking DTC memory.
- Check A/C compressor status using "Read Measuring Value Block" function 08. Read Measuring Value Block (VAG 1551 Function 08)
- A/C compressor switch-off conditions must not exist in order to proceed, as described in 'Read Measuring Value Block.'
- Switch A/C on.
- Insert scan tool "AC/Heating Electronics" address word 08.

Indicated on display:
Rapid data transfer HELP
Select function XX
- Press "HELP" button to print out list of available functions.
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.

Indicated on display:
Rapid data transfer Q
03 - Output Diagnostic Test Mode
Press -Q- button to confirm input.

Indicated on display:
Output Diagnostic Test Mode
A/C compressor engagement
or
00624 ->
Output check: 0270 (info from literature)

Check "A/C compressor engagement" only if one or more of the following conditions exist:
- Idle speed too high-pre-control value for Idle Air Control (IAC) too high
- A/C compressor does not engage, and code "5" appears in measuring value block display field 1
- Engine speed (RPM) fluctuates or idle is irregular during A/C operation
- Malfunction "A/C compressor engagement - short circuit to positive" displayed
Press -> button.

Indicated on display:
Output Diagnostic Test Mode ->
A/C Clutch - N25
- A/C clutch is switched on and off in 3 second intervals
- A/C compressor is driven with A/C clutch engaged
- Press -> button.

NOTE: If "Function is unknown or cannot be carried out at the moment" appears in the display after the A/C clutch is switched on, check DTC memory once again. There is a malfunction that is only recognized during the output DTM.

If the A/C clutch does not engage, or the A/C compressor does not rotate when the clutch engages:
- Check battery positive voltage (B+) supply to A/C clutch (using wiring diagram).
- With ignition switched off, check A/C compressor by hand for ease of movement.
- Repair A/C clutch.

Checking Output DTM "A/C Compressor Engagement:"
- Switch ignition off and wait 30 seconds.
- Remove Engine Control Module (ECM), See Powertrain Management.
- Connect VAG1598 test box to ECM connectors A, B and C, using VAG 1598/11 and / or VAG1598/12 adapters.
- Connect VAG1527B voltage tester between test box sockets 11 (input for compressor engagement, terminal 87a from A/C clutch control module -J153-) and 45 (GND). See Wiring diagrams.
- Start engine.

Indicated on display (Operating modes -1- and -2- appear alternately):
V.A.G - ON BOARD DIAGNOSTIC HELP
1 - Rapid data transfer
2 - Blink code output
Press -1- button to select "Rapid data transfer" operating model.

Indicated on display:
Rapid data transfer HELP
Insert address word XX
Press buttons -0- and -8- to select "AC/Heating Electronics" address word 08.

Indicated on display:
Rapid data transfer Q
08 - AC/Heating Electronics
Press -Q- button to confirm input.

Indicated on display:
4A0919579 F Ctl. Air Cond. XXX DXX ->
Press -> button.

Indicated on display:
Rapid data transfer HELP
Selection function XX
Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.

Indicated on display:
Rapid data transfer Q
03 - Output Diagnostic Test Mode
Press -Q- button to confirm input.

Indicated on display:
Output Diagnostic Test Mode ->
A/C compressor engagement
LED (VAG1527B voltage tester) should blink on and off in 3-seconds intervals.
or
00624 ->
Output check: 0270 (info from literature)
If LED does not blink:
- Check wiring for open or short circuit between A/C clutch control module -J153- and ECM -J192- harness connector according to wiring diagrams, and repair as necessary.
- Press -> button.

Indicated on display:
Output Diagnostic Test Mode ->
A/C Clutch - N25
- A/C clutch is switched on and off in 3 second intervals
- A/C compressor is driven with A/C clutch engaged
- Press -> button.