P0977
DTC P0976 or P0977
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0976
- Shift Solenoid Valve 2 Control Circuit Low Voltage
DTC P0977
- Shift Solenoid Valve 2 Control Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
Shift Solenoid Valve 2 is installed on the middle valve body. The solenoid turns ON and OFF in response to signals output from the TCM. According to the ON or OFF status of Shift Solenoid Valve 1 or Shift Solenoid Valve 2, the 1st gear engine brake operates or the gear shifts into change. As a fail-safe function, if any shift solenoid abnormality occurs, the transmission control module (TCM) will disable the current to the solenoids.
Conditions for Running the DTC
P0976
* The ignition voltage is 10.2-15.5 V.
* The engine speed is greater than 400 RPM for 2 s.
* The transmission is not in emergency mode.
* 10 ms after solenoid output changed.
P0977
* The ignition voltage is 10.2-15.5 V.
* The engine speed is greater than 400 RPM for 2 s.
* The transmission is not in emergency mode.
* 10 ms after solenoid output changed.
Conditions for Setting the DTC
P0976
The TCM detects an OFF signal (0 V) of the Shift Solenoid Valve 2 circuit when the Shift Solenoid Valve 2 is commanded ON (12 V) for 100 ms continuously after 5 times.
P0977
The TCM detects an ON signal (12 V) of the Shift Solenoid Valve 2 circuit when the Shift Solenoid Valve 2 is commanded OFF (0 V) for 100 ms continuously after 5 times.
Action Taken When the DTC Sets
* DTCs P0976 and P0977 are Type A DTCs.
* The TCM freezes transmission adaptive functions.
* The TCM turns OFF all solenoids.
* The TCM allows the vehicle to operate only in the second gear and reverse (R) range after a stop.
Conditions for Clearing the DTC
* DTCs P0976 and P0977 are Type A DTCs.
* The TCM detects an ON signal (12 V) of the Shift Solenoid Valve 2 circuit when the Shift Solenoid Valve 2 is commanded ON (12 V) for 1 s continuously.
* The TCM detects an OFF signal (0 V) of the 2 circuit when the Shift Solenoid Valve 2 is commanded OFF (0 V) for 1 s continuously.
Diagnostic Aids
When attempting to set solenoid electrical DTCs, ensure the control solenoid valve assembly is warmed up and the transmission is operated long enough to ensure a 3°C (37°F) increase in temperature. This will place the TCM in the optimal conditions to test solenoid electrical DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics AF40-6 (MDK) - Automatic Transmission
Connector End View Reference
Component Connector End Views Sunshade - Left
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Description and Operation
Transmission Component and System Description Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Engine running, ensure the transmission fluid temperature is between 50-80°C (122-176°F).
2. Engine running in Park position, parking brake applied, place the gear select lever in each gear position for 2-3 s. Return the gear select lever to the Park position. Place the gear selector in Reverse for 5 s and then idle vehicle for 5 s.
3. Verify the scan tool data Shift Solenoid Valve 2 parameter displays ON.
• If the parameter not displayed ON
Refer to Circuit/System Testing
• If the parameter displays ON
4. Operate the vehicle within the Conditions for Running the DTC. It may be helpful to operate the vehicle within the conditions identified from the Freeze Frame/Failure Records data.
• If the DTC is set
Refer to Circuit/System Testing
• If the DTC is not set
5. All OK.
Circuit/System Testing
1. Ignition OFF, and all vehicle systems OFF. Remove the K71 Transmission Control Module to disconnect the X2 harness connector. It may take up to 2 min for all vehicle systems to power down.
2. Test for 11-15 ohms between the control circuit terminal 2 at the X2 harness connector and ground.
• If not between 11-15 ohms
1. Disconnect the wiring harness from the Q32B Shift Solenoid Valve 2, refer to Automatic Transmission Wiring Harness Replacement Service and Repair
2. Test the wiring harness for infinite resistance between the control circuit terminal 2 and ground.
• If less than infinite resistance, replace the wiring harness
• If infinite resistance
3. Test the wiring harness for less than 2 ohms in the control circuit terminal 2 and the harness connector at the Q32B Shift Solenoid Valve 2 end to end.
• If 2 ohms or greater, replace the wiring harness
• If less than 2 ohms
4. Test the wiring harness for less than 1 V between the control circuit terminal 2 and ground.
• If 1 V or greater, replace the wiring harness
• If less than 1 V
5. Test for less than 2 ohms in the ground circuit at the Q32B Shift Solenoid Valve 2 end to end.
• If 2 ohms or greater, replace the wiring harness
• If less than 2 ohms
6. Perform the Control Solenoid Valve Inspection AF40-6 (MDK) - Automatic Transmission
• If a defect is found, replace the control valve body.
• If no defect found, replace the K71 Transmission Control Module.
• If between 11-15 ohms
3. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.
• If the DTC is set
Replace the K71 Transmission Control Module.
• If the DTC is not set
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Wiring harness replacement, refer to Automatic Transmission Wiring Harness Replacement Service and Repair
* Control valve body replacement, refer to Control Valve Body Replacement Control Valve Body Replacement
* Refer to Control Module References Control Module References for TCM replacement, programming and setup.
* Perform the Transmission Adaptive Functions Transmission Adaptive Functions.