Test sequence

• Connect Scan Tool VAG 1551 ((VAG 1552) 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; see VAG 1551 SCAN TOOL, CONNECTING .)

Indicated on display:

• Press buttons -0- and -3- for the function "Output Diagnostic Test Mode".

Indicated on display:

• Confirm input with -Q- button.

Indicated on display:

• Press the --> button.

Indicated on display:

• press --> the button.

Indicated on display:

A/C compressor switch-off is checked.

A/C compressor must stop within 5 seconds (visual check) then start approx. every 5 seconds and then stop.

If the A/C compressor is not switched off:

• Proceed with function 3: Output DTM, until complete.
• Press buttons -0- and -6- for the function "End output" and confirm entry with the -Q- button.
• Switch off ignition.
• Remove wiper arms and plenum cover:

See Plenum Cover Emoval & Installation

• Connect test box VAG 1598/31 to control unit wiring harness.
Fig 6: Connecting Test Box VAG 1598/31 To Control Unit Wiring Harness
Courtesy of VOLKSWAGEN OF AMERICA, INC.
• Check wiring between test box socket 29 and the A/C system for open circuit using wiring diagram. Wire resistance: Max. 1.5 Ω
• Check DTC memory and, if necessary, repair any malfunctions and then erase; see DIAGNOSTIC TROUBLE CODE (DTC) MEMORY, CHECKING AND ERASING .
• Read readiness code, see READING READINESS CODE . If the DTC memory has been erased or the Diesel Direct Fuel Injection Engine Control Module -J248- was disconnected from permanent battery positive (B+), the readiness code must be generated again; see READINESS CODE, SETTING .