Leak Detection Pump (ldp) V144 , Checking Audi TT 8N

Special tools, testers and auxiliary items required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. Fuse S234 OK.
2. The Fuel Pump (FP) Relay J17 OK.
3. The ignition switched off.

Test procedure

1. Perform a preliminary check to verify the customers complaint. Refer to --> «General Diagnosis»(ref-276276-S40851803372008010300000) .
2. Remove the left rear wheel housing liner. Refer to --> «66 EXTERIOR EQUIPMENT»(ref-276287-S36131290332008010300000)

Start diagnosis

1. Remove the right front wheel.
2. Remove the right front wheelhousing liner.

Scheme 15

1. Disconnect the Leak Detection Pump (LDP) V144 electrical harness connector - 3 -.

Checking internal resistance

Scheme 16

1. Using a Multimeter , check the Leak Detection Pump (LDP) V144 for resistance as follows

If any of the specifications are not obtained

1. Replace the Leak Detection Pump (LDP) -V144-. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000)

If the specified values are obtained

Checking voltage supply

Note. The voltage for the Leak Detection Pump (LDP) -V144- is supplied by the Fuel Pump (FP) Relay J17.

Scheme 17

1. Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 3 for voltage.

1. Operate the starter briefly.

Specified value: battery voltage.

1. Switch the ignition off.

If the specified value was not obtained

1. Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 3 to the Fuel Pump (FP) Relay J17 socket 19/86 for resistance.

Specified value: 1.5 ohms max

If the specification was not obtained

1. Check the wiring for a short circuit to Battery positive (+) or an open circuit.
2. Check the electrical harness connector for damage, corrosion, loose or broken terminals.
3. If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK

Checking wiring

If the manufacturers test box is being used. Perform the following step.

1. Install the test box VAG1598/31. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000)

If the manufacturers test box is not being used. Perform the following step.

1. Remove the Motronic Engine Control Module (ECM) J220. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .
2. Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 1 to Motronic Engine Control Module (ECM) J220 electrical harness connector terminal 80 for resistance.

1. Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 2 to Motronic Engine Control Module (ECM) J220 electrical harness connector terminal 25 for resistance.

Specified value: 1.5 ohms max.

If the specification is not obtained

1. Check the wiring for a short circuit to Battery positive (+), Ground (GND) or an open circuit.
2. Check the electrical harness connector for damage, corrosion, loose or broken terminals.
3. If necessary, repair the faulty wiring connection.

If no malfunction is found in wiring

1. Erase the DTC memory. Refer to --> «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000) .
2. Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to --> Readiness Code .

1. End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

1. Replace the Motronic Engine Control Module (ECM) J220. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .
2. Assembly is performed in the reverse of the removal.

Final procedures

After the repair work, the following work steps must be performed in the following sequence

1. Check the DTC memory.
2. If necessary, erase the DTC memory. Refer to «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «Readiness Code»(ref-276276-S05799074302008010300000) .

End of diagnosis