Corvette V8-6.2L (2008)
Throttle Body: Procedures
Throttle Learn
Throttle Learn
Description
The engine control module (ECM) learns the airflow through the throttle body to ensure the correct idle. The learned airflow values are stored within the
ECM. These values are learned to adjust for production variation and will continuously learn during the life of the vehicle to compensate for reduced
airflow due to coking. Anytime the throttle body airflow rate changes, for example due to cleaning or replacing, the values must be relearned.
A vehicle that had a heavily coked throttle body that has been cleaned or replaced may take several drive cycles to learn out the coking. To accelerate the
process, the scan tool has the ability to reset all learned values back to zero. A new ECM will also have values set to zero.
The idle may be unstable or a DTC may set if the learned values do not match the actual airflow.
Conditions for Running the Throttle Learn Procedure
With Scan Tool - Reset Procedure
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DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0171, P0172, P0174, P0175,
P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0300, P0351, P0352, P0353, P0496, P0601, P0604, P0606, P060D, P0641,
P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, or P2176 is not set.
*
Ignition ON, engine OFF.
*
The vehicle speed sensor (VSS) is 0 km/h (0 mph).
Without Scan Tool - Learn Procedure
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DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0171, P0172, P0174, P0175,
P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0300, P0351, P0352, P0353, P0496, P0601, P0604, P0606, P060D, P0641,
P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, or P2176 is not set.
*
The engine speed is between 450-4,000 RPM.
*
The manifold absolute pressure (MAP) is greater than 5 kPa.
*
The mass air flow (MAF) is greater than 2 g/s.
*
The ignition 1 voltage is greater than 10 volts.
Throttle Learn
With Scan Tool - Reset Procedure
1. Ignition ON, engine OFF, with a scan tool, perform the Idle Learn Reset in Module Setup.
2. Start the engine, monitor the TB Idle Airflow Compensation parameter. The TB Idle Airflow Compensation value should equal 0 percent and the
engine should be idling at a normal idle speed.
3. Clear the DTCs and return to the diagnostic that referred you here.
Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Computers and
Control Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions) .
Without Scan Tool - Learn Procedure
1. Start and idle the engine in PARK for 3 minutes.
2. With a scan tool, monitor desired and actual RPM.
3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
4. Ignition OFF for 60 seconds.
5. Start and idle the engine in PARK for 3 minutes.
6. After the 3 minute run time the engine should be idling normal.
Important: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM
can continue to learn.
‹› If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations
and extended idles.
7. After the drive cycle, the engine should be idling normally.
‹› If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 6.
