2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1575

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1575

- Drive Motor 1 Position Learn Incorrect

DTC P1B10

- Drive Motor 2 Position Learn Incorrect

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, 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.

Conditions for Running the DTC

Condition 1, 2, 3 and 4

* Hybrid wake-up signal is not active because the ignition has been transitioned from RUN to OFF.

* The MCM has learned a valid drive motor position sensor offset value at least once.

Condition 2

Motor speed is less than 20 RPM.

Conditions for Setting the DTC

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.

Action Taken When the DTC Sets

* P1B10 and P1B0F are Type C DTCs.

* The MCM operates the drive motor generator using the last valid learned offset.

Conditions for Clearing the DTC

* P1B10 and P1B0F are Type C DTCs.

* High voltage remains enabled immediately following an ignition key transition from RUN to OFF.

Reference Information

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

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

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