P215C
DTC P215C
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC P215C
- Output Shaft Speed (OSS) - Wheel Speed Correlation
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The output speed sensor (OSS) assembly has 2 internal hall-effect type sensors, and is capable of sensing both speed and direction. The OSS mounts to the A/Trans case assembly and is connected to the control solenoid (w/body and TCM) valve assembly through a wire harness and connector. The sensor faces the front differential drive pinion (w/transfer gear) gear assembly machined teeth surface. The sensor receives 8.3-9.3 volts on the OSS supply voltage circuit from the transmission control module (TCM). As the output shaft rotates, the sensor produces a signal frequency based on the machined surface of the output shaft.
The two sensor elements in the OSS assembly are spaced approximately 1/2 a tooth apart.
* When the vehicle is moving in a forward direction, sensor A detects a particular tooth before sensor B.
* When the vehicle is moving in a reverse direction, sensor B detects a particular tooth before sensor A.
The electronics in the sensor combine the two signals and send a signal with a different pulse width. This signal is interpreted by the TCM for speed and direction and is transmitted through the GMLAN circuits to the engine control module (ECM) and the hybrid powertrain control module (HPCM). The ECM, HPCM, and TCM compare the OSS signal with the ABS wheel speed sensor signal.
Conditions for Running the DTC
* The vehicle is moving.
* The TCM correlates the transmission output speed with the ABS wheel speed and motor speed to detect any failures in the transmission output speed sensor.
Conditions for Setting the DTC
Fail Case 1
The difference between transmission output speed and the calculated average of output speed from the drive motors and ABS wheel speed sensors is greater than 400 RPM, the output speed calculated from the ABS wheel speeds sensors, and the output speed calculated from the drive motor speeds is less than 150 RPM for 200 milliseconds.
Fail Case 2
The difference between the transmission output speed and the calculated average of output speed from the drive motors and the ABS wheel speed sensors is greater than 200 RPM, when the output speed calculated from wheel speeds and output speed calculated from the drive motor speeds is greater than 150 RPM for 200 milliseconds.
Action Taken When the DTC Sets
* P215C is a Type B DTC.
* The TCM calculates output speed based on the ABS wheel speed and the drive motor speed signals.
* The TCM calculates vehicle speed based on the wheel speed sensors.
Conditions for Clearing the DTC
P215C is a Type B DTC.
Diagnostic Aids
Inspect the OSS, harness, connector pins for metallic debris and output shaft machined face for damage or misalignment. Proper torque of the OSS mounting bolt is critical to proper OSS operation.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information.
Special Tools
J 38522 - Variable Signal Generator
Circuit/System Verification
Operate the vehicle at 16-32 km/h (10-20 mph) while observing the Transmission OSS and ABS wheel parameters on the scan tool. Inspect for the following mechanical conditions:
* Loose, misaligned, OSS
* Broken driveline components
The OSS and ABS wheel speed signal displays should not vary by greater than 10 km/h (6 mph).
Circuit/System Testing
1. Ignition OFF, remove the control valve body cover. Refer to Control Valve Lower Body and Upper Body Replacement (2MT70 - Automatic Transmission).
2. Connect the TCM harness connector.
3. Disconnect the output speed sensor (OSS) harness connector from the control solenoid (w/body and TCM) valve assembly.
4. Connect the J 38522 - variable signal generator between the supply voltage terminal B and OSS signal terminal A at the control solenoid (w/body and TCM) valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Output Shaft Speed Input Test (Control Solenoid Valve and Transmission Control Module Assembly Output Shaft Speed Input Test) for further instructions.
5. Set the J 38522 - variable signal generator signal to 8 volts, the frequency to 120 and the percent duty cycle to 50.
6. Ignition ON, observe the scan tool Transmission OSS parameter. The scan tool Transmission OSS parameter should be between 100-400 RPM.
• If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
7. Test the output speed sensor harness for an open, short to ground or short to voltage.
• If all circuits test normal, test or replace the output speed sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Perform the Automatic Transmission Wiring Harness and Output Speed Sensor Removal (Overhaul) and Automatic Transmission Wiring Harness and Output Speed Sensor Installation (Overhaul) for OSS replacement.
* Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.