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, or resolver, contains a drive coil, two driven coils and an irregular shaped metallic rotor. The metallic rotor is mechanically attached to the shaft of the drive motor generator. At ignition ON, the MCM outputs a 7 volt ac, 10 kHz excitation signal to the drive coil. The drive coil excitation signal creates a magnetic field surrounding the two driven coils and the irregular shaped rotor. The MCM then monitors the two driven coil circuits for a return signal. The position of the irregular shaped metallic rotor causes the magnetically-induced return signals of the driven coils to vary in size and shape. A comparison of the two driven coil signals allows the MCM to determine the exact position, speed and direction of the drive motor generator.

The position sensor is a non-serviceable part of the drive motor generator assembly.

A measurement called offset is needed for accurate determination of the motor position. Offset is the relationship between the position sensor and the drive motor generator output shaft. Whenever the ignition is cycled to OFF, the MCM attempts to learn the offset of the drive motor position sensor by rapidly oscillating the motor and observing the position sensor signals.

Condition 1, 2, 3 and 4

Condition 2

Motor speed is less than 20 RPM.

Condition 1

Position sensor offset value not learned because drive motor speed is greater than 50 RPM.

Condition 2

Position sensor offset value not learned because hybrid battery voltage as observed at the MCM is less than 192V.

Condition 3

Position sensor offset value not learned because drive motor phase to phase current difference is less than 15 A.

Condition 4

Position sensor offset value not learned because the offset learn value is greater than the maximum allowed offset of 25 degrees.

Scan Tool Reference

Control Module References for scan tool information

1. Observe the BECM Contactor Sys. Req. Signal parameter. The HV contactor relays should be Closed, enabling the high voltage system.

⇒	If the HV contactor relays are Open, diagnose and repair the DTCs which are preventing high voltage from being enabled.

2. Ignition OFF, wait 2 minutes.
3. Ignition ON, wait 2 minutes and then turn ignition OFF.
4. Ignition ON, monitor DTC Status. DTC P1B10 and P1B0F should have passed last test.

⇒	If the DTC has passed, clear DTC Information. No further diagnosis of this DTC is necessary.

1. Inspect for DTCs P0A40, P0A45, P0A46, P0A78, P0A79, P0A3F, P0C05, P0C08, P0C0B, P0C0E, P0C4E, P0C4F, P0C52, P0C53, P0C57, P0C58, P0C61, P0C62, P0C5C, P0C5D, P1B03, P1B04 or P1B0D.

⇒	If any of the above DTCs are set, diagnose and repair them prior to performing this diagnostic.

2. Ignition ON, engine OFF. Observe the BECM Hybrid Battery Pack Calculated parameter. The hybrid battery voltage should be greater than 192V.

⇒	If the hybrid battery voltage is less than 192V, replace the drive motor generator battery.

3. Turn the ignition OFF and wait 2 minutes.
4. Ignition ON, monitor DTC Status. DTC P1B10 and P1B0F should have passed last test.

⇒	If DTC P0C4E or P0C4F sets, proceed to that diagnostic procedure.

⇒	If DTC P1B10 and P1B0F have passed, clear DTC Information. No further diagnosis is necessary.

⇒	If DTC P1B10 or P1B0F 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 applicable drive motor generator assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.