Activating leak detection pump (LDP) V144 :

• Press → key.

Indicated on display:

Output Diagnostic Test Mode (DTM) → Leak Detection Pump (LDP) Tank vent. system

Leak detection pump must start up in intervals.

If leak detection pump does not start running:

• Disconnect 3-pin connector from Leak Detection Pump (LDP) V144.
• Pull connector off solenoid valve - 1  - and connect voltage tester VAG1527B with auxiliary cables from VAG1594 to disconnected connector contacts 2 + 3.

LED must flash

LED flashes:

• Proceed with Output Diagnostic Test Mode until completed.
• Switch ignition off.
• Replace Leak Detection Pump (LDP) V144. → 20 - FUEL SUPPLY
• Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory → DTC memory (functions 02 and 05), checking and erasing 

• Read readiness code → Readiness code, reading  . If DTC memory has been erased, readiness code must be generated again:

Engine code AWW, → Readiness code for engine code AWW, generating 

Engine code AWP, → Readiness code for engine code AWP, generating 

LED does not flash:

• Proceed with Output Diagnostic Test Mode until completed.
• Switch ignition off.

• Connect test box VAG1598/31 to control module wiring harness. Engine control module remains disconnected.
• Check wire between test box socket 80+3 pin connector contact 2 for open circuit using wiring diagram.

Wire resistance: max. 1.5 Ω

• Check wire between test box socket 25+3 pin connector contact 2 for open circuit using wiring diagram.

Wire resistance: max. 1.5 Ω

• Additionally check wire for short to battery positive and Ground (GND).

If no malfunction in wire is detected:

• Check wire between 3 pin connector contact 3 and fuel pump (FP) relay J17 for open circuit using wiring diagram.

Wire resistance: max. 1.5 Ω

If no wiring malfunction is detected:

• Replace engine control module → Engine control module, replacing  .