Leak Detection Pump Checking/Can-Bus Data Exchange (GROUP 24, NO. 97-03)
Publication date: 1997-10-27Reference number: GROUP 24, NO. 97-03
LEAK DETECTION PUMP CHECKING/CAN-BUS DATA EXCHANGE
TECHNICAL SERVICE BULLETIN
LEAK DETECTION PUMP (LDP), CHECKING CAN-BUS DATA EXCHANGE (MOTRONIC/ABS), CHECKING
Model(s): 1998-on Audi A8
Group: 24 - Multiport Fuel Injection
Bulletin No.: 97-03
Date: October 27, 1997
File this Technical Bulletin in Repair Manual No.: W42 015 196 102.
SERVICE INFORMATION
The repair information that follows is new and will be integrated with the next Repair Manual update.
UPDATE TO REPAIR GROUP 24
- A note should be added to the Repair Manual index to refer to this Technical Bulletin for information on checking the CAN-bus between the Motronic ECM and the ABS control module.
- There is also a CAN-bus between the Motronic ECM and the Transmission TCM. Take care to choose the correct procedures when being referred to the checking of a CAN-bus circuit.
LEAK DETECTION PUMP (LDP) -V144-, CHECKING
ELECTRICAL CHECK
Disconnect harness connector for Leak Detection Pump (LDP) -V 144-.
Connect multimeter US1119 (Fluke 83 or equivalent) between terminals -1- and -3- of LDP and check resistance. See Fig 1 .
- Specified value: 640 - 720 ohm
Connect multimeter US1119 (Fluke 83 or equivalent) between terminals -2- and -3- of LDP and check resistance.
- Specified value: 17.5 - 27.5 ohm
If resistance is not OK:
Replace leak detection pump.
VOLTAGE SUPPLY, CHECKING
Disconnect harness connector for LDP -V144-.
Connect VAG 1527B LED voltage tester between connector terminal -3- (B+) and engine Ground (GND). See Fig 2 .
Start engine and let idle.
- LED must light up.
If LED does not light:
Check fuse for LDP -V144-.
Check wiring for open circuit between terminal -3- and fuse, according to wiring diagram.
- Specified value: max. 0.5 ohm
Check fuel pump relay.
CAN-BUS DATA EXCHANGE BETWEEN MOTRONIC ECM AND ABS CONTROL MODULE, CHECKING
DTC table indicates that CAN-bus be checked.
Check DTC memory of ABS control module. See Repair Manual, ABS/EDL/ASR On Board Diagnostic (OBD), Repair Group 01.
If a DTC pertaining to the CAN-bus is stored:
Switch ignition off.
Connect VAG 1598/19 test box to ECM harness connector.
Check wiring from terminals C1 and C19 on Engine Control Module (ECM) to ABS control module for open or short circuit. See Fig 1 . See Electrical Wiring Diagrams, Troubleshooting & Component Locations binder.
If wiring connection is OK, replace either ABS control module or ECM.