A4 Sedan L4-1.8L Turbo (AEB) (1997)
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Idle Speed: Testing and Inspection
Idle Speed, Checking
NOTE:
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Idle speed, ignition timing and CO-content cannot be adjusted.
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Idle speed is maintained by the Throttle valve control module.
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CO-content is maintained and adjusted by Oxygen Sensor (O2S) control. Malfunctions in O2S control are recognized by On Board Diagnostic
(OBD) and stored in DTC memory.
Required special tools and test equipment
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VAG 1551 Scan Tool (ST) with VAG 1551/3 adapter cable
Test conditions
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No malfunctions stored in DTC memory.
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Engine Coolant Temperature (ECT) at least 85 °C (185 °F)
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All electrical consumers switched off (radiator coolant fan must not run during test)
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A/C switched off
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Exhaust system free of leaks
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Automatic transmission selector lever in "P" or "N" position
Checking
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Connect VAG 1551 or VAG 1552 scan tool and press buttons -0- and -1- to insert "Engine Electronics" address word O1 (with engine running at
idle). Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/1552 Scan Tool" See: Powertrain
Management/Computers and Control Systems/Testing and Inspection
Indicated on display
Rapid data transfer
HELP
Select function XX
-
Press buttons -0- and -4- to select "Basic Setting" function 04, and press -Q- button to confirm input.
Indicated on display
System in Basic Setting
HELP
Input display group number XXX
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Press buttons -0-, -0- and -1- to input display group number 1, and press -Q- button to confirm input.
Indicated on display (1-4 = display fields)
System in Basic Setting 1
->
1 2 3 4
NOTE:
After selecting function 04, the ECM initiates the following:
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EVAP canister purge regulator valve is closed
-
A/C compressor is switched off
Continue with the test only when the operating conditions in display field 4 are satisfied.
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Briefly raise engine speed (acceleration burst) and let engine run at idle for another 2 minutes.
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Compare display with specified values (display fields 1-4):
