Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P16F4: Control Module Transmission Range Control PerformanceTypical Scan Tool Data
IMS Circuits/Parameter | Selector Position | ||||
|---|---|---|---|---|---|
Park | Reverse | Neutral | Drive | Manual | |
Direction Switch Operating Conditions: Ignition ON, range selector in appropriate gear | |||||
Direction IMS D1 | HIGH | HIGH | LOW | LOW | LOW |
Direction IMS D2 | LOW | LOW | HIGH | HIGH | HIGH |
Direction IMS R1 | HIGH | LOW | LOW | HIGH | HIGH |
Direction IMS R2 | LOW | HIGH | HIGH | LOW | LOW |
Direction IMS Start | LOW | HIGH | LOW | HIGH | HIGH |
Range Switch Operating Conditions: Ignition ON, range selector in appropriate gear | |||||
IMS A | LOW | LOW | HI | HI | HI |
IMS B | HI | LOW | LOW | LOW | HI |
IMS C | HI | HI | HI | LOW | LOW |
IMS P | LOW | HI | LOW | HI | LOW |
Always HIGH status: Open/short to voltage condition Always LOW status: Short to ground condition Every status HIGH for either switch indicates an open ground circuit or connector for that portion of the IMS. | |||||
Circuit/System Description
The internal mode switch (IMS) assembly is a sliding contact switch attached to the control valve body within the transmission. The nine outputs from the switch indicate which position is selected by the transmission manual shaft. Four outputs (A, B, C, P), are range selection inputs to the transmission control module (TCM). Five outputs (R1, R2, D1, D2, S) are direction selection inputs to the hybrid powertrain control module (HPCM). The input voltage at the module is high when the switch is open and low when the switch is closed to ground.
The HPCM compares the IMS range position to the IMS direction position to verify the transmission direction is correct.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | Ignition voltage is 8-18 volts. |
Conditions for Setting the DTC
Condition 1
The transmission direction, indicated by both the IMS range and direction switch circuits, are valid but do not match.
Condition 2
| • | One IMS direction switch circuit has failed. |
| • | The HPCM calculates a transmission direction base upon the remaining IMS direction circuits. |
| • | The calculated HPCM transmission direction does not match the direction indicated by the IMS range switch circuits. |
Condition 3
| • | One IMS direction switch circuit has failed. |
| • | The HPCM calculates a transmission direction based upon the remaining IMS direction circuits. |
| • | The IMS range switch indicated a transitional position. |
Condition 4
| • | One IMS direction switch circuit has failed. |
| • | The HPCM calculates a transmission direction based upon the remaining IMS direction circuits. |
| • | The TCM has indicated at least one IMS range switch circuit has failed. |
Condition 5
| • | More than one IMS direction circuit has failed and the HPCM cannot calculate a transmission direction. |
| • | The IMS range switch indicates a transitional position. |
Condition 6
| • | More than one IMS direction circuit has failed and the HPCM cannot calculate a transmission direction. |
| • | The TCM has indicated at least one IMS range switch circuit has failed. |
Action Taken When the DTC Sets
| • | DTC P16F4 is a Type A DTC. |
| • | The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays. |
Conditions for Clearing the DTC
DTC P16F4 is a Type A DTC.
Diagnostic Aids
If IMS circuit DTCs P181C-P181F, P183A-P183F, P184A or P184B are set, perform those diagnostics first.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
| • | DT-47825-10 Jumper Harness |
| • | DT-48493 Jumper Harness |
Circuit/System Verification
- Clear the DTC information.
- Turn the ignition OFF for 1 minute.
- Turn the ignition ON.
- 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.
- Retest for DTC P16F4.
| ⇒ | If the Direction IMS operation does not match the logic table proceed with Circuit/System Testing. |
| ⇒ | If the IMS A/B/C/P operation does not match the logic table proceed to DTC P1824, P182A-P182F, P1838, or P1839 . |
| ⇒ | If 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
- 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.
- 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.
- 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.
- 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.
- Disconnect the IMS connector at the switch.
| ⇒ | If a signal displays LOW, disconnect the PIM connector X1 and test the circuit for a short to ground. |
| ⇒ | If the circuit tests normal, replace the PIM. |
| ⇒ | If 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. |
| ⇒ | If the circuit tests normal, replace the PIM. |
| ⇒ | If 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. |
| ⇒ | If the circuit tests normal, replace the PIM. |
| ⇒ | If 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. |
| ⇒ | If 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.
Important: Connect one end of the DT-48493 to the transmission connector. Use the other end as the terminal testing point.
| ⇒ | Test 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.
| ⇒ | Test 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. |
| ⇒ | If the circuit, including the TCM, tests normal, replace the IMS switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Control Module References for PIM or TCM replacement, setup, and programming. |
