2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1833
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, cycle the Tow/Haul switch while observing the Tow/Haul switch parameter on the scan tool in the Transmission Controls Data
list. The Tow/Haul switch parameter should change states from NO to YES, or YES to NO with each cycle of the switch.
2. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle
within the conditions that you observed from the Freeze Frame/Failure Records.
Circuit/System Testing
1. Ignition OFF, transmission in Park. Disconnect the automatic transmission shift lever electrical connector.
2. Ignition OFF, test for less than 1 ohm between terminal 2 on the automatic transmission shift lever vehicle harness connector and ground at
the battery negative post.
瀚慖f greater than the specified value, test the ground circuit for an open/high resistance.
3. Ignition ON, test for greater than 11 volts on the signal circuit terminal 1 on the automatic transmission shift lever vehicle harness connector
and ground at the battery negative post.
瀚慖f not within the specified value, test the signal circuit for a short to ground or an open/high resistance. If all circuits test normal, replace
the BCM.
4. Ignition OFF, test for less than 3 ohms between terminal 1 and terminal 2 on the automatic transmission shift lever component harness
connector while depressing the Tow/Haul switch button.
瀚慖f greater than the specified value, replace the automatic transmission shift lever assembly.
5. If all circuits test normal, replace the BCM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Control Module References (See: Testing and Inspection/Programming and Relearning)for BCM replacement, setup, and programming.
* Automatic Transmission Range Selector Lever Replacement (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Shift
Linkage/Service and Repair)
P077B
DTC P077B
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 P077B
- Output Speed Sensor Direction Incorrect
Diagnostic Fault Information
Typical Scan Tool Data
