P0960
DTC P0960-P0963
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 P0960
-
Main Modulation/Line Pressure Control (PC) Solenoid Control Circuit Open
DTC P0961
-
Pressure Control (PC) Solenoid 1 System Performance
DTC P0962
-
Main Modulation/Line Pressure Control (PC) Solenoid Control Circuit Low Voltage
DTC P0963
-
Main Modulation/Line Pressure Control (PC) Solenoid Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The modulated main pressure control (PC) solenoid valve is a normally closed (N/C) solenoid that regulates transmission line pressure. This solenoid is used to reduce line pressure when the vehicle is not moving with engine at idle, thus decreasing engine load and also improving cooler flow. The transmission control module (TCM) commands the modulated main PC solenoid valve ON when specific transmission and engine conditions are met. When the modulated main PC solenoid valve is commanded ON, control main pressure is routed to the main regulator valve lowering the line pressure.
The TCM provides B+ to the modulated main PC solenoid valve, torque converter clutch (TCC) pressure control (PC) solenoid, and pressure control solenoid valve 1 (PCS1) through a separate solid state device called high side driver 1 (HSD1). The TCM uses a low side driver to switch the modulated main PC solenoid valve ON and OFF.
Conditions for Running the DTC
P0960, P0962, or P0963
* DTC P0657, P0658, or P0659 is not set.
* Battery voltage is between 9-18 V.
* Engine speed is greater than 200 RPM.
* HSD1 is enabled.
P0961
* DTC P0657, P0658, P0659, P0960, P0961, or P0962 is not set.
* Battery voltage is between 9-18 V.
* Engine speed is greater than 200 RPM.
* HSD1 is enabled.
Conditions for Setting the DTC
P0960
TCM detects an open circuit on the modulated main PC solenoid valve control circuit for 1 second.
P0961
TCM detects the modulated main PC solenoid valve current does not equal the commanded modulated main PC solenoid valve current for 40 seconds.
P0962
TCM detects a short to ground on the modulated main PC solenoid valve control circuit for 1 second.
P0963
TCM detects a short to voltage on the modulated main PC solenoid valve circuit for 1 second.
Action Taken When the DTC Sets
P0960 or P0961
* DTCs P0960 and P0961 are Type A DTCs.
* Main Modulation/Line Pressure Control is disabled.
P0962 or P0963
* DTCs P0962 and P0963 are Type A DTCs.
* Main Modulation/Line Pressure Control is disabled or the transmission will lock into range.
Conditions for Clearing the DTC
DTCs P0960, P0961, P0962, and P0963 are Type A DTCs.
Diagnostic Aids
P0960
* You may have to drive the vehicle in order to experience a condition.
* If DTC P0960 is accompanied by DTC P2727 and or DTC P2761, the open is most likely in the HSD1 circuit.
P0962 or P0963
You may have to drive the vehicle in order to experience a condition.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
* Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
* Inline Harness Connector End Views X100
Description and Operation
* Transmission General Description Transmission General Description
* Transmission Component and System Description Transmission Component and System Description
* Electronic Component Description Electronic Component Description
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
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. Ignition ON, engine OFF. Command the Modulated Main Pres. Ctrl. Sol. ON and OFF with a scan tool. The Line PC Sol. Pressure Command parameter should change from 0 kPa (0 psi) to 1600 kPa (232 psi).
• If the parameter does not change between the specified values
Refer to Circuit/System Testing below.
• If the parameter changes between the specified values
2. Clear the TCM DTCs.
3. Perform the Road Test Initial Inspection and Diagnostic Overview. Verify with a scan tool that DTC P0960, P0961, P0962 or P0963 did not set.
• If DTC P0960, P0961, P0962 or P0963 set
Refer to Circuit/System Testing below.
• If DTC P0960, P0961, P0962 or P0963 did not set
4. After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
Note:
You must perform the Circuit/System Verification first.
1. Ignition OFF, disconnect the 20-way X175 vehicle harness connector at the transmission.
2. Ignition ON, engine OFF.
3. Verify that a test lamp illuminates between the vehicle harness X175 transmission connector B+ circuit terminal L and ground.
• If the test lamp does not illuminate
1. Ignition OFF, disconnect the 80 way vehicle harness connector at the K71 transmission control module.
2. Test for infinite resistance between the X175 vehicle harness transmission connector B+ circuit terminal L and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms between the X175 vehicle harness transmission connector B+ circuit terminal L and the vehicle harness transmission control module connector terminal 11.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K71 transmission control module.
• If the test lamp illuminates
4. Connect a test lamp between the X175 vehicle harness transmission connector modulated main pressure control (PC) solenoid valve control circuit terminal S and the B+ circuit terminal L.
5. Command the Modulated Main Pres. Ctrl. Sol. ON and OFF with a scan tool and verify the Line PC Sol. Pressure Command parameter changes from 0 kPa (0 psi) to 1600 kPa (232 psi). The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON
1. Ignition OFF, disconnect the 80 way vehicle harness connector at the K71 transmission control module.
2. Test for infinite resistance between the X175 vehicle harness transmission connector modulated main pressure control (PC) solenoid valve control circuit terminal S and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K71 transmission control module.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the 80 way vehicle harness connector at the K71 transmission control module.
2. Test for less than 2 ohms between the X175 vehicle harness transmission connector modulated main pressure control (PC) solenoid valve control circuit terminal S and the vehicle harness transmission control module connector terminal 74.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms
3. Ignition ON.
4. Test for less than 1 volt between the X175 vehicle harness transmission connector modulated main pressure control (PC) solenoid valve control circuit terminal S and ground.
• If 1 volt or greater, repair the short to voltage in the circuit.
• If less than 1 volt, replace the K71 transmission control module.
• If test lamp turns ON and OFF
6. Ignition OFF, install the X175 harness connector at the transmission.
7. Remove the transmission oil pan. Refer to Oil Pan Replacement Service and Repair.
8. Disconnect the modulated main pressure control (PC) solenoid valve connector.
9. Connect a test lamp between the transmission internal harness modulated main pressure control (PC) solenoid valve connector B+ circuit terminal A and control circuit terminal B.
10. Ignition ON, engine OFF.
11. Command the Modulated Main Pres. Ctrl. Sol. ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp does not turn ON and OFF
Replace the transmission internal wiring harness. Refer to Wiring Harness Replacement Service and Repair.
• If the test lamp turns ON and OFF
12. Ignition OFF, disconnect the 80 way vehicle harness connector at the K71 transmission control module.
13. Test for infinite resistance between the transmission internal harness modulated main pressure control (PC) solenoid valve connector control circuit terminal B and ground.
• If less than infinite resistance
Repair the short to ground on the circuit.
• If infinite resistance
14. Test for less than 2 ohms between transmission internal harness modulated main pressure control (PC) solenoid valve connector control circuit terminal B and the vehicle harness transmission control module connector terminal 74.
• If 2 ohms or greater
Repair the open/high resistance in the circuit.
• If less than 2 ohms
15. Replace the modulated main pressure control (PC) solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Wiring Harness Replacement Service and Repair
* Control Valve Solenoid Replacement (PCS1 and PCS2) Control Valve Solenoid Replacement (PCS1 and PCS2)Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD)
* Control Module References Control Module References for TCM replacement, programming, and setup
Repair Verification
If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.