Service Information

Volt

DTC P16F4

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 Switch Input Circuitry Performance

The automatic transmission manual shift shaft position switch assembly, also called the internal mode switch assembly, contains two sliding hall-effect switch assemblies attached to the control valve body within the transmission. The 9 outputs from the switches 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. The Range input signals are represented as TCM scan tool parameters, Internal Mode Switch A, B, C, and P. The Direction input signals are represented as hybrid powertrain control module scan tool parameters, Internal Mode Switch 2 - R1, R2, D1, D2, and S. The input voltage at the modules is high when a switch is open and low when a switch is closed to earth. Each control module independently supplies power and earth to its respective switch assembly.

The hybrid powertrain control module is internal to the power inverter module, often referred to as the drive motor generator power inverter module and is not serviced separately. The hybrid powertrain control module compares the internal mode switch requested direction to other data to verify that the indicated direction and range switch calculation is correct.

Conditions for Running the DTC

•	The vehicle is ON.

•	Ignition voltage is greater than 9.5 V.

Conditions for Setting the DTC

Condition 1

The transmission direction, indicated by both the internal mode range and direction switch circuits, are valid but do not match.

Condition 2

•	One internal mode direction switch circuit has failed.

•	The hybrid powertrain control module calculates a transmission direction based upon the remaining internal mode direction circuits.

•	The calculated hybrid powertrain control module transmission direction does not match the direction indicated by the internal mode range switch circuits.

Condition 3

•	One internal mode direction switch circuit has failed.

•	The hybrid powertrain control module calculates a transmission direction based upon the remaining internal mode direction circuits.

•	The internal mode range switch indicates a transitional position.

Condition 4

•	One internal mode direction switch circuit has failed.

•	The hybrid powertrain control module calculates a transmission direction based upon the remaining internal mode direction circuits.

•	The TCM has indicated the internal mode range switch parameter is invalid.

Condition 5

•	More than one internal mode direction circuit has failed and the hybrid powertrain control module cannot calculate a transmission direction.

•	The internal mode range switch indicates a transitional position.

Condition 6

•	More than one internal mode direction circuit has failed and the hybrid powertrain control module cannot calculate a transmission direction.

•	The TCM has indicated the internal mode range switch parameter is invalid.

Action Taken When the DTC Sets

•	DTC P16F4 is a Type A DTC.

•	The hybrid powertrain control module requests the hybrid powertrain control module 2 to open the high-voltage contactor relays.

Conditions for Clearing the DTC

DTC P16F4 is a Type A DTC.

Reference Information

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify that DTC P181C, P181D, P181E, P181F, P183A, P183B, P183C, P183D, P183E, P184A, or P184B is not set.

⇒	If any of the DTCs are set, refer to DTC P181C-P181F, P183A-P183E, P184A, or P184B .

Verify that DTC P1824, P182A, P182B, P182C, P182D, P182E, P182F, P1838, or P1839 is not set.

⇒	If any of the DTCs are set, refer to DTC P1824, P182A-P182F, P1838 or P1839 .

Verify that DTC P16F4 is not set.

⇒	If the DTC is set, program the hybrid powertrain control module. If the DTC resets, replace the T6 power inverter module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Drive Motor Generator Power Inverter Module, also called the power inverter module, replacement, programming and set-up.