Engine Control Module: Testing and Inspection
Special tools, testers and auxiliary items
- VAG 1551/1552 Scan Tool using VAG 1551/3 adapter cable
- VAG 1598/18 Test Box
- Fluke 83 multimeter (or equivalent)
- VW 1594 Adapter kit
- Wiring diagram
Test sequence
- Connect VAG 1551 (VAG 1552) Scan Tool. Refer to Scan Tool Testing/VAG 1551 Scan Tool. Testing and Inspection
- With ignition switched on but engine not running, press buttons -0- and -1- to select "Engine electronics" address word 01.
Display will appear as shown
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read measuring value block"
- Press -Q- button to enter selection.
Display will appear as shown
Read measuring value block HELP
Input display group number XXX
- Press buttons -0-, -0- and -2- to select "Display group number 2".
- Press -Q- button to enter selection.
Display will appear as shown (1 to 4 = Display fields)
Read measuring value block 2 ->
1 2 3 4
- Check battery voltage (Display field 3)
Display Group 5:
- Press -> button.
- Press buttons -0- and -6- to select "End output" and press -Q- button to confirm input.
Evaluating display group 2
Voltage supply terminal 30, checking
- Switch ignition off.
- Connect VAG 1598/18 Test Box to ECM wiring harness.
- Switch Fluke 83 multimeter to 20 Volt DC range.
- Connect multimeter between Test Box sockets 1 + 54 using jumper wires from VW 1594 adapter kit.
- specification: 12 to 14.5 Volts
If specification not obtained:
- Check wiring using wiring diagram.
Voltage supply terminal 15, checking
- Switch ignition off.
- Connect VAG 1598/18 Test Box to ECM wiring harness.
- Switch ignition on.
- Connect multimeter between Test Box sockets 1 + 23 using jumper wires from VW 1594 adapter kit.
- specification: 12 to 14.5 Volts
If specification not obtained:
- Check wiring using wiring diagram
Procedure after voltage supply open circuit
If the voltage supply is interrupted, the engine control module loses all learned and/or "basic" values.
Special tools and equipment
- VAG 1551/1552 Scan Tool using VAG 1551/3 adapter cable
Work sequence
Perform the following operations after voltage supply open circuit:
- Switch ignition on for at least 10 seconds.
- Switch ignition off.
- Match engine control module to throttle valve control module
- Perform idling check. Testing and Inspection
NOTE: During the idling check the EVAP purge regulator solenoid valve and the air conditioner are switched off and the oxygen control learning procedure is initiated.
- Perform a longer road test until any poor driveability characteristics are eliminated.
During the road test the following operational conditions must be fulfilled:
- The coolant temperature must exceed 80 °C
- When the above temperature is reached, idling, part throttle, wide open throttle and overrun must be attained several times.
- At wide open throttle the engine speed must exceed 3500 rpm