2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 914
Diagnostic Procedures/MP 3010-NP0/Transfer Case High/Low Clutch Reset)
* Transfer Case Two/Four Wheel Drive Actuator Replacement (See: Powertrain Management/Transmission Control Systems/Actuators and
Solenoids - Transmission and Drivetrain/Actuators and Solenoids - Transfer Case/Transfer Case Actuator/Service and Repair/MP 3010-NP0
- Transfer Case/Transfer Case Two/Four Wheel Drive Actuator Replacement)
* Transfer Case Disassemble (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP 3010-NP0 - Transfer
Case/Transfer Case Disassemble)
* Transfer Case Assemble (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP 3010-NP0 - Transfer
Case/Transfer Case Assemble)
* Oil Pump Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP 3010-NP0 - Transfer
Case/Oil Pump Cleaning and Inspection)
* Rear Output Shaft Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP 3010-NP0 -
Transfer Case/Rear Output Shaft Cleaning and Inspection)
* Front Output Shaft and Input Shaft Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and
Repair/Overhaul/MP 3010-NP0 - Transfer Case/Front Output Shaft and Input Shaft Cleaning and Inspection)
* Drive Chain, Drive Sprocket, and Driven Sprocket Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and
Repair/Overhaul/MP 3010-NP0 - Transfer Case/Drive Chain, Drive Sprocket, and Driven Sprocket Cleaning and Inspection)
* Two/Four Wheel Drive Shift Components Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and
Repair/Overhaul/MP 3010-NP0 - Transfer Case/Two/Four Wheel Drive Shift Components Cleaning and Inspection)
* Transfer Case Front Half Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP
3010-NP0 - Transfer Case/Transfer Case Front Half Cleaning and Inspection)
* Transfer Case Rear Half Cleaning and Inspection (See: Transmission and Drivetrain/Transfer Case/Service and Repair/Overhaul/MP
3010-NP0 - Transfer Case/Transfer Case Rear Half Cleaning and Inspection)
MP 3023/3024-NQH - Transfer Case
DTC C0387
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC C0387 59
- Unable to Complete Shift Circuit
Diagnostic Fault Information
Circuit/System Description
The transfer case encoder motor (TCEM) is a bi-directional, permanent magnet, DC motor. When energized, through motor control A or motor
control B, the ground is provided by the opposing motor control circuit and then grounded through the transfer case shift control module (TCCM)
ground circuit, the TCEM, through a series of gears, rotates the transfer case control actuator shaft which moves the transfer case two/four wheel
drive actuator cam and transfer case high/low shift fork to shift the transfer case between the following modes or ranges:
* 2WD HI
* 4WD Auto
* 4WD HI
* 4WD LO
* Neutral
If the shift lever detent shaft were to bind, or there was a mechanical failure, or motor A control and motor B control were shorted together the shift
would not be completed. This will cause the DTC to set in order to protect system components from damage.
Conditions for Running the DTC
* Ignition ON.
* System voltage 10.5-18 V.
