A4 Quattro Sedan V6-2.8L (ACK) (1997)
Idle Speed: Adjustments
CHECKING IDLE SPEED
NOTES:
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Idle speed can NOT be manually adjusted.
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Idle speed is checked during "Basic Setting" function 04, refer to Diagnosis with Scan Tool, Address Word 01/Basic Setting/Display Group
Diagnostic Charts See: Computers and Control Systems/Testing and Inspection. After selecting function 04, the learning values for idle speed
and oxygen sensor control are relearned (idle speed and CO content are adjusted independently).
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CO content is controlled by oxygen sensor control for a specified value. Interference within oxygen sensor control will be captured via the On
Board Diagnostic system and stored in DTC memory.
Test Conditions
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No leaks in exhaust system.
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Engine Coolant Temperature: 85°C (185°F) minimum.
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Throttle valve in closed throttle position. Adjust accelerator pedal cable if necessary.
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All electrical consumers switched OFF.
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A/C switched OFF.
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Pressure measuring devices NOT connected.
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Automatic transmission vehicles: selector lever in "P" or "N".
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Check DTC memory: There should be no malfunctions stored.If necessary;
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Repair malfunction.
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Erase DTC memory.
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stop engine (switch ignition OFF) and start again.
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Test drive and check DTC memory again to make sure no malfunctions are stored.
NOTE: Erasing DTC memory resets the readiness code (as well as with address word 01, "Basic Setting" function 04 and address word 33, mode
4).
WARNING: Do not take any measurements while the radiator coolant fan is running.
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Using VAG 1551 scan tool, select "Basic Setting" function 04, input display group number 003, and advance until the display shows "Basic
Setting 3".
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Display will appear as shown: (1 to 4 = Display fields)
Basic Setting
3
1 2 3 4.
NOTE:
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Continue with test, if the engine coolant temperature exceeds 85°C (185°F) ~ display group 001, display field 1.
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Basic Setting" function 04 the EVAP canister purge regulator valve -N80- is closed.
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Briefly increase engine speed (RPM) and then let idle for another 2 minutes.
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Observe value in display field 1.
Specified Value: 650 to 750 RPM.
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Push ENTER button.
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Push buttons -0- and -6- to select "End Output" function 06.
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Press -Q- button to confirm input.
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If the specified value is not obtained:
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Check DTC memory again.
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If the idle speed is too high and there are no malfunctions stored in DTC memory:
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Check Closed Throttle Position (CTP) switch.
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Check for large intake air leak.
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Check Idle Air Control (IAC) valve.
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Check learning values for Idle Speed Control (ISC).
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If the idle speed is too low and there are no malfunctions stored in DTC memory:
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Check Closed Throttle Position (CTP) switch.
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Check Idle Air Control (IAC) valve.