Circuit Description
The TCM uses the line pressure control (PC) solenoid valve in order to regulate the transmission line pressure. The line PC solenoid valve is attached to the control solenoid valve assembly. The TCM compares TP angle signal, transmission fluid temperature, speed ratio, and other inputs in order to determine the line pressure appropriate for a given load. The TCM regulates the pressure by applying a varying amperage to the line PC solenoid valve. The applied amperage varies from 0.1 amps for maximum line pressure to 1.1 amps for minimum line pressure. The TCM then monitors the amperage at the return line.
When the TCM detects a significant difference between commanded and actual current in the PC solenoid valve circuit, DTC P0961 sets. DTC P0961 is a type B DTC.
Conditions for Running the DTC
| • | No Line PC Solenoid DTCs P0960, or P0962. |
| • | The engine speed is greater than 500 RPM for 5 seconds. |
Conditions for Setting the DTC
The TCM detects that the actual current flowing through the circuit is outside of a calibrated current threshold for the current commanded duty cycle for 2 seconds.
Action Taken When the DTC Sets
| • | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The TCM no longer inhibits shifting to between reverse and drive when moving. |
| • | The TCM commands maximum pressure to the input clutch. |
| • | The TCM freezes garage shift transmission adaptive functions. |
| • | The TCM freezes main line pressure transmission adaptive functions. |
| • | The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
| • | The TCM stores DTC P0961 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met. |
Conditions for Clearing the MIL/DTC
| • | The ECM turns OFF the MIL after the third consecutive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the MIL/DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM. |
Diagnostic Aids
| • | Inspect the connectors at the TCM, the transmission, and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents . |
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 2.2L (L61) | ||||
2 |
Important:
Does the DTC fail this condition? | -- | Go to Step 3 | Go to Intermittent Conditions in Engine Controls - 2.2L (L61) | ||||
3 | Using the scan tool, monitor Ignition Voltage. Is Ignition Voltage below the specified value? | 11 V | Refer to DTC P0562 | Go to Step 4 | ||||
4 | Test the low control circuit of the line PC solenoid valve for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | Go to Step 13 | Go to Step 5 | ||||
5 |
Is the resistance value within the specified range? | 2.8-6.8ohms | Go to Step 10 | Go to Step 6 | ||||
6 | Using the DMM and the J-35616 Connector Adapter Test Kit, measure the resistance between the line PC solenoid valve high control and the line PC solenoid valve low control circuits. Is the resistance less than the specified value? | 2.8ohms | Go to Step 7 | Go to Step 8 | ||||
7 | Test the high control circuit for a short to the low control circuit of the line PC solenoid valve. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||
8 |
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 | ||||
9 | Inspect for faulty connections at the transmission. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||
10 | Inspect for faulty connections at the TCM. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||
11 | Replace the line PC solenoid valve. The line PC solenoid valve is part of the control solenoid valve assembly. Refer to Control Valve Body Assembly Disassemble . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||
12 | Replace the TCM. Refer to Transmission Control Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 14 | Go to Step 2 | ||||
14 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.2L (L61) | System OK |
