2. Clear the DTCs with a scan tool. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power
down.
3. Ignition ON, observe the scan tool TAC Motor parameter. The reading should display Enabled.
4. Observe the DTC information with a scan tool. DTC P1516, P2101, P2119, or P2176 should not set.
Note:
* If the Throttle Sweep Test is not available on the scan tool, use the accelerator to perform the test. Refer to Diagnostic Aids for further
details.
* If there is a condition with the throttle body, the TAC Motor Command parameter will go to 99 % for a predetermined amount of time
and then a DTC sets. Once a DTC is set, the TAC Motor Command parameter will go to 0 % and the TAC Motor parameter will display
Disabled.
5. Perform the Throttle Sweep Test while observing the TAC Motor parameter with a scan tool. The TAC Motor parameter should display
Enabled while the Throttle Sweep Test is in progress.
Note: Before replacing the throttle body assembly, make sure the throttle control circuits are not shorted to B+.
锟斤拷If not the specified value, replace the throttle body assembly.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Warning
Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.
1. Ignition OFF, verify the following conditions do not exist with the throttle body assembly:
* A throttle blade that is not in the rest position
* A throttle blade that is binding open or closed
* A throttle blade that is free to move open or closed without spring pressure
锟斤拷If a condition is found, replace the throttle body assembly.
Note: Disconnecting the throttle body harness connector may cause additional DTCs to set.
2. Ignition OFF, disconnect the harness connector at the throttle body assembly.
3. Ignition ON, verify that a test lamp does not illuminate between each control circuit listed below and ground.
* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B
锟斤拷If test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify that a test lamp does not illuminate between each control circuit listed below and B+.
* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B
锟斤拷If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
5. Ignition OFF, set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.
Note:
* The DMM Min/Max Recording Mode and the response time of 1 ms must be reset after testing each circuit or a lower voltage will be
recorded.
* The ignition must be OFF and the ECM completely powered down before testing each circuit or a lower voltage will be recorded.
6. Ignition OFF, measure the voltage using the DMM Min/Max Recording Mode function on each circuit listed below as the ignition is turned
ON. The Max voltage should be within 1 V of B+.
* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B
锟斤拷If not within the specified range, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
7. If all circuits and connections test normal, replace the throttle body assembly.
