Pinout Values and Diagnostic Parameters
Electrical testingWiring and component testing using VAG 1598 Test Box and VAG 1598/18 adapter cable
^ For testing, use hand multimeter (Fluke 83 or equivalent) and US 1115 LED tester.
^ Specified values are valid for ambient temperatures from 0 to 40°C (32 to 104°F).
^ If measured values vary from specified values, check component wiring using wiring diagrams.
^ If measured values vary only slightly from specified values, clean test box terminals, connectors and test leads, then repeat test. Before replacing components, check wiring and connections, especially when specified values are less than 10 Ohms.
CAUTION! Switch multimeter to the appropriate measuring range before connecting the test leads to avoid damaging the electronic components.
^ To connect the multimeter to the VAG 1598 test box, use adapter leads from VW 1594 adapter kit.
^ The connector terminal numbers match the socket numbers on the VAG 1598 test box.
Test conditions:
^ Battery Positive Voltage (B+) OK
^ Fuses 15 (S15),18 (S18)and 21 (S21) 0K
^ Ground (GND) connection on engine and transmission OK
^ Fuel Pump OK
^ Fuel Pump (FP) Relay (J17) OK
Electrical testing:
- Switch ignition OFF.
- Disconnect harness connector -1- from Mono-Motronic Engine Control Module (ECM) (J257) -2-.
^ ECM (J257) -2- located in plenum.
- Connect VAG 1598 test box to ECM wiring harness connector using VAG 1598/18 adapter cable.
- Perform electrical tests according to table.
CAUTION! Switch multimeter to the appropriate measuring range before connecting the test leads to avoid damaging the electronic components.
Note: For cars with automatic transmission, the Diagnostic Trouble Code (DTC) "Engine/Transmission electrical connection: disconnected", caused when the Mono-Motronic Engine Control Module was disconnected, must be erased.
Test Steps 1 - 6:
Test Steps 7 - 10a:
Test Steps 11 - 15:
Test Steps 16 - 17:
Test Steps 18 - 19:
Note: For vehicles with automatic transmission, the wiring to the Transmission Control Module (TCM) (terminals 9 + 34) is tested by checking the automatic transmission Diagnostic Test Mode. (DTM)
Fig. 1 - Temperature Sensor Resistance:
^ Engine Coolant Temperature (ECT) Sensor (G62)
^ Intake Air Temperature (IAT) Sensor (G72)