2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1769
Circuit/System Verification
1. Clear the DTC information.
2. Turn the ignition OFF for 1 minute.
3. Turn the ignition ON.
4. Test for correct operation of the direction and range IMS switch circuits in every gear selection. Hold the selector in each gear position for at
least 2 seconds. Refer to Typical Scan Tool Data.
瀚慖f the Direction IMS operation does not match the logic table proceed with Circuit/System Testing.
瀚慖f the IMS A/B/C/P operation does not match the logic table proceed to DTC P1824, P182A-P182F, P1838, or P1839 ( See: P Code
Charts/P1824).
5. Retest for DTC P16F4.
瀚慖f the DTC resets, program the PIM with the latest software version and recheck for DTCs. If the DTC resets after programming or if the
PIM already contains the latest software version, replace the PIM.
Circuit/System Testing
1. Disconnect the transmission X176 24-way connector. Ignition ON. The scan tool IMS Status parameter should display HI for the R1, R2, D1,
D2 and S signal circuit displays.
瀚慖f a signal displays LOW, disconnect the PIM connector X1 and test the circuit for a short to ground.
瀚慖f the circuit tests normal, replace the PIM.
2. Install DT-48493 to the vehicle harness connector X176. Verify that a test lamp illuminates between the Direction IMS switch ground circuit
and battery positive.
瀚慖f the test lamp does not illuminate, disconnect PIM connector X1 and test the ground circuit for an open, high resistance or short to
voltage condition.
瀚慖f the circuit tests normal, replace the PIM.
3. Connect a 3-amp fused jumper wire between each Direction IMS signal circuit at DT-48493 and the ground circuit terminal. The scan tool
parameter should display LOW for each signal circuit when grounded.
瀚慖f a scan tool parameter always displays HIGH, disconnect PIM connector X1 and test the circuit for an open, high resistance or short to
voltage condition.
瀚慖f the circuit tests normal, replace the PIM.
4. Disconnect the transmission 16-way X175 connector. Install DT-47825-10 to the vehicle harness. Connect a 3-amp fused jumper wire
between the Starter signal circuit terminal and ground. The scan tool parameter should display LOW when the signal circuit is grounded.
瀚慖f the scan tool parameter always displays HIGH, disconnect PIM connector X1 and test the circuit for an open, high resistance or short to
voltage condition.
瀚慖f the circuit tests normal, replace the PIM.
Important: The remaining diagnostic steps test the internal transmission components and circuits. The automatic transmission fluid
pan assembly must be removed in order to perform the diagnostic tests.
5. Disconnect the IMS connector at the switch.
Important: Connect one end of the DT-48493 to the transmission connector. Use the other end as the terminal testing point.
瀚慣est the direction signal circuits and the ground circuit between the IMS and the transmission 24-way X176 connector for a short to
ground, open, high resistance or short to voltage condition.
Important: Connect one end of the DT-47825-10 to the transmission connector. Use the other end as the terminal testing point.
瀚慣est the Starter signal circuit between the IMS and the transmission 16-way X175 connector for a short to ground, open, high resistance
or short to voltage condition. The TCM is a pass-through of the Starter signal circuit and should be tested as a typical circuit path.
瀚慖f the circuit, including the TCM, tests normal, replace the IMS switch.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Control Module References (See: Testing and Inspection/Programming and Relearning) for PIM or TCM replacement, setup, and
programming.
* Manual Shift Shaft Position Switch Replacement (See: Powertrain Management/Computers and Control Systems/Sensors and Switches -
