2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2437
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
瀚慖f 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
瀚慖f 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
瀚慖f 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.
Repair Instructions
* Throttle Body Assembly Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and
Repair/Removal and Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement,
programming, and setup
Repair Verification
1. Install any components that have been removed or replaced during diagnosis.
2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
3. Clear the DTCs with a scan tool.
4. Turn OFF the ignition for 60 s.
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.
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.
6. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in
order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List -
Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) and perform the appropriate diagnostic
procedure.
P1629
DTC P1629
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
