Diagnostic Instructions
DTC Descriptor
DTC P1B0D: Drive Motor 1 Control Module Drive Motor 1 Overspeed
DTC P1B0E: Drive Motor 2 Control Module Drive Motor 2 Overspeed
Circuit/System Description
The drive motor generator position sensor is monitored by the motor control module (MCM). The MCM monitors the angular position, speed and direction of the drive motor generator based upon the signals of the resolver-type position sensor. The position
sensor allows the MCM to determine the exact position, speed and direction of the drive motor generator.
Conditions for Running the DTC
| • | Ignition voltage is 8-18 volts. |
| • | MCM temperature and voltage out of range DTCs have not set. |
| • | Drive motor generator speed greater than 11,500 RPM. |
Conditions for Setting the DTC
The MCM detects drive motor generator speed greater than 10,000 RPM after an initial detection of greater than 11,500 RPM.
Action Taken When the DTC Sets
| • | DTCs P1B0D and P1B0E are Type A DTCs. |
| • | The hybrid powertrain control module (HPCM) commands the battery energy control module (BECM) to open the high voltage contactor relays. |
Conditions for Clearing the DTC
DTCs P1B0D and P1B0E are Type A DTCs.
Diagnostic Aids
| • | The drive axle and drive motor generator 2 are joined mechanically through a planetary gear set, any condition that allows the rear axle to rotate too fast while the transmission is in gear may cause DTC P1B0E to set. Ask the operator
if the vehicle was subjected to downhill coasting at an excessive speed. |
| • | A transmission mechanical failure that occurs during high drive motor generator torque may cause these DTCs to set. |
| • | Any condition which causes either MCM to receive incorrect or corrupt GM LAN information may cause these DTCs to set. Inspect for communication DTCs. |
| • | Repeated drive motor generator operation at speeds in excess of the DTC limits may cause deterioration of the drive motor generator magnets. |
Reference Information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Verification
- Inspect for transmission control module (TCM) DTC P0723, any other DTCs that would indicate an internal transmission mechanical concern or any vehicle communication U-code DTCs.
- Clear the DTC information.
- Turn the ignition OFF for 1 minute.
Important: DTC P1B0E may be the result of driving conditions or habits.
- Operate the vehicle under the conditions for running.
- Retest for DTCs P1B0D and P1B0E.
| ⇒ | 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. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for PIM replacement, setup, and programming.
