S5 Quattro Coupe V8-4.2L (CAUA) (2009)
Engine Control Module: Testing and Inspection
ECM Voltage Supply, Checking
ECM Voltage Supply, Checking
Special tools, testers and auxiliary items required
‹› Multimeter.
‹› Wiring Diagram.
Test requirements
‹› Fuse (SB4) OK.
‹› Fuse (SB6) OK.
‹› The Ground (GND) connections at the engine and transmission OK.
‹› The battery voltage at least 12.5 V.
‹› The generator OK.
Test procedure
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Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] See: Testing and Inspection/Scan Tool Testing
and Procedures/Preliminary Check.
Start diagnosis
If the manufacturers test box is being used, perform the following step.
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Install the test box.
If the manufacturers test box is not being used, perform the following step.
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Remove the Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] See: Service and Repair/Engine
Control Module, Replacing.
Checking voltage supply
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Using a Multimeter, check the following wiring connection for voltage.
Specified value: 12.5 V
If the specified value was not obtained:
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Check the Motronic Engine Control Module (ECM) (J623) electrical harness connector T94 terminal 92 to the Battery (A) positive terminal for an
open circuit or short to Ground (GND).
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Check the electrical harness connectors for damage, corrosion, loose or broken terminals.
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If necessary, repair the wiring connection.
If no malfunctions are found in the wiring:
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Switch the ignition on.
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Using a Multimeter, check the following wiring connections for voltage.