Pinout Values and Diagnostic Parameters
Terminal Resistance For CAN-Bus, Checking
Function
Control module for Diesel-Direct fuel injection system communicates with other CAN-Bus capable control modules.
The databus-capable control modules are connected via two databus wires which are
twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the data bus is recognized as an error by both the control module for Diesel-Direct fuel injection system and by other CAN-Bus control modules.
Trouble-free operation of the CAN-Bus requires that it have a terminal resistance. This central terminal resistance is located in control module for Diesel-Direct fuel injection system.
Recommended special tools and equipment
- V.A.G 1598/18 Adapter - 68-pin (vehicles with 80-pin control module and autom. transmission)
- V.A.G 1598/21 Adapter for V.A.G 1598 (25-pin) (vehicles with 80-pin control module and manual transmission)
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram
Test requirements
- DTC "P0600 Serial Communication Link" was detected by the control module for Diesel-Direct fuel injection system, Diagnostic mode 3: Check DTC memory. Diagnostic Mode 3: Check DTC Memory
- Ignition switched off.
Test sequence
Vehicles with 80-pin control module and manual transmission
Vehicles with 80-pin control module and autom. transmission.
- Remove air filter housing.
- Disengage connector from ABS control module and disconnect.
- Connect VAG1598/21 -1- test box to ABS control module wiring harness -2-.
- Check the terminal resistance in control module for Diesel-Direct fuel injection system.
- To do this, measure resistance between test box sockets 10 +11:
Specified value: 115...135 Ohm
If resistance value is not in specified range:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If resistance value is in specified range:
- Check CAN data bus wires for short circuit to each other.
- Remove wiper arms and wind cowl.
- Disengage connectors from control module for Diesel-Direct fuel injection system and disconnect the connectors.
- Measure resistance anew between test box sockets 10 +11:
Specified value: Infinite Ohm
If specified value is obtained (wires have no short circuit to each other):
- Eliminate error in wires according to wiring diagram.
- Erase DTC memory of control module for Diesel- Direct fuel injection system, Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
Vehicles with 80-pin control module and autom. transmission
- Remove wiper arms and wind cowl:
- Disconnect connector (arrow) from Transmission Control Module (TCM).
- Connect V.A.G 1598/18 Adapter - 68-pin to wiring harness of Transmission Control Module (TCM) -1- and engage the connector -2-.
- Check CAN-Bus wires with terminal resistances in ECM and ABS control module:
- To do this, measure resistance between test box sockets 3 +25:
Specified value: 55...75 Ohm
If resistance value is not in specified range:
- Continue test according to the following table:
If resistance value is in specified range:
- Check CAN data bus wires for short circuit to each other:
- Disengage connectors from control module for Diesel-Direct fuel injection system and disconnect the connectors.
- Remove air filter housing.
- Disengage connector from ABS control module and disconnect.
- Measure resistance anew between test box sockets 3 +25:
Specified value: Infinite Ohm
If specified value is obtained (wires have no short circuit to each other):
- Eliminate error in wires according to wiring diagram:
Continuation at 115 to 135 Ohm
- Disengage connectors from control module for Diesel-Direct fuel injection system and disconnect the connectors.
- Check CAN-Bus wires with terminal resistance in ABS control module:
- To do so, measure resistance anew between test box sockets 3 +25:
Specified value: 115...135 Ohm
If resistance value is not in specified range:
- Check CAN-Bus wires.
If wires to ABS control module are OK:
- Replace ABS control module.
- Erase DTC memory of control module for Diesel- Direct fuel injection system, Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If resistance value is in specified range:
- Re-connect connectors to control module for Diesel-Direct fuel injection system.
- Remove air filter housing.
- Disengage connector from ABS control module and disconnect.
- Check CAN-Bus wires with terminal resistance in control module for Diesel-Direct fuel injection system.
- To do so, measure resistance anew between test box sockets 3 +25:
Specified value: 115...135 Ohm
If resistance value is not in specified range:
- Check CAN-Bus wires.
If no malfunctions are detected in wires:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
Checking CAN-Bus wires
- Remove air filter housing.
- Disengage connector from ABS control module and disconnect.
- Disengage connectors from control module for Diesel-Direct fuel injection system and disconnect the connectors.
- Check CAN data bus wires for short circuit to each other.
- To do so, measure resistance anew between test box sockets 3 + 25 at V.A.G 1598/18 Adapter - 68-pin:
Specified value: Infinite Ohm
If specified value is not obtained (wires have shorts):
- Eliminate error in wires according to wiring diagram.
- Erase DTC memory of control module for Diesel-Direct fuel injection system, Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specified value is obtained (wires have no short circuit to each other):
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
- Check CAN-Bus wires between test box sockets for open circuit according to wiring diagram:
Socket 68 (1598/22) and Socket 3 (1598/18)
Socket 75 (1598/22) and Socket 25 (1598/18)
Wire resistance: max. 1.5 Ohm
- Also check wires for short circuits to B+ or Ground (GND).
If no malfunctions are detected in wires:
- Connect VAG1598/21 -1- test box to ABS control module wiring harness -2-.
- Check CAN-Bus wires between test box sockets 1598/22 and 1598/21 for open circuit according to wiring diagram:
Socket 68 (1598/22) and Socket 10 (1598/21)
Socket 75 (1598/22) and Socket 11 (1598/21)
Wire resistance: max. 1.5 Ohm
Vehicles with 121-pin control module
- Connect test box to control module for Diesel- Direct fuel injection system, connect test box for wiring test. During this, wiring harness to Engine Control Module (ECM) is not connected. Test Box, Connecting For Wiring Test
- Check the central terminal resistance in control module for Diesel-Direct fuel injection system.
- To do this, measure resistance between test box sockets 6 +7.
Specified value: 60...72 Ohm
If resistance value is not in specified range:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If resistance value is in specified range:
- Remove test box from control module for Diesel- Direct fuel injection system.
- Connect test box to control module wiring harness.
- Check CAN data bus wires for short circuit to each other.
- To do this, perform a resistance measurement anew between test box sockets 58 + 60:
Specified value: Infinite Ohm
If specified value is obtained (wires have no short circuit to each other):
- Eliminate error in wires according to wiring diagram.