Test sequence
- Disconnect cover -1- on left in engine compartment.
- Unbolt coolant expansion tank (arrow).
- Disconnect electrical wiring to Engine Coolant Level (ECL) warning switch -F66- on bottom of expansion tank.
- Lay coolant expansion tank with connected coolant hoses -1- to -3- aside.
- Remove bolts (arrows) on left cylinder head.
- Disconnect 4-pin connectors -4- to -6- on ignition coils.NOTE: For further testing, the multimeter is attached to an ignition coil connector.
- Connect multimeter as follows to measure voltage.
Courtesy of AUDI OF AMERICA, INC.
IGNITION COIL POWER OUTPUT STAGE CONNECTOR TERMINAL 1 VOLTAGE REFERENCEConnector
terminalMeasure to 1 Engine ground - Switch ignition on.
- Specified value: approx. battery voltage
If specified value is not attained:
- Switch ignition off.
- Pull off rubber seal of plenum chamber cover.
- Remove plenum chamber cover -1- toward front (arrows).
- Pry off both trim caps -3- with a screwdriver.
- Undo hex nuts -4- a few turns.
- Release wiper arms -2- from pivot shaft by tilting them slightly.
- Remove hex nuts completely and remove wiper arms.
- Disconnect retaining clips -1- and remove air cowl grille -5-.
- Remove cover for electronics box (plenum chamber) (arrows).
- Lift off engine control module retaining clip using a screwdriver (arrow) and move control module to side.
- If installed, unclip transmission control module retaining clip and place control module on one side.
- Disconnect power supply relay -2-.
- Check for open circuit in following wiring according to wiring diagram:
Courtesy of AUDI OF AMERICA, INC.
IDENTIFYING TERMINAL 1 & 8 SPECIFICATIONS (ECM POWER SUPPLY RELAY)Relay carrier in electronics box, plenum chamber, position 2
terminalConnection of ignition coils
terminal8 1 - Repair open circuit, if necessary.
If no wiring malfunction is detected:
- Check voltage supply of Motronic Engine Control Module (ECM) power supply relay -J271-. See CHECKING POWER SUPPLY .
- Check actuation of Motronic Engine Control Module (ECM) power supply relay -J271-. See CHECKING ACTUATION .
Fig 6: Prying Off Trim Caps, Removing Hex Nuts & Wiper Arms, Disconnecting Retaining Clips & Removing Air Cowl Grille