• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
PC Solenoid High Control | P0961 | P0961 | P0961 | P0961 |
PC Solenoid Low Control | P0961 | P0961 | P0961 | P0961 |
Circuit | Normal | Short to Ground | Open/High Resistance | Short to Voltage |
---|---|---|---|---|
Operating Conditions: Engine running in PARK, normal operating temperature Parameter Normal Range: 0.02-1.10 amps | ||||
PC Sol. Actual Current | 0.02-1.10 amps | Less than 0.02 amps | Less than 0.02 amps | Less than 0.02 amps |
PC Sol. Ref. Current | 0.02-1.10 amps | Less than 0.02 amps | Less than 0.02 amps | Less than 0.02 amps |
The pressure control (PC) solenoid valve is located in the valve body. The PC solenoid valve controls transmission line pressure based on current flow through the windings. The transmission control module (TCM) determines desired line pressure based on throttle position and other inputs. The TCM then varies the duty cycle on the high side of the PC solenoid valve to control current flow to the solenoid. Current is controlled from about 0.02 amp for maximum line pressure to 1.1 amps for minimum line pressure. The TCM monitors the actual current to the solenoid.
The PC solenoid valve is enabled.
The PC solenoid duty cycle is outside the range of 0.5-95 percent for 4 seconds.
• | DTC P0961 is a type C DTC. |
• | The TCM commands maximum line pressure. |
• | The TCM freezes transmission adaptive functions. |
DTC P0961 is a type C DTC.
Automatic Transmission Controls Schematics
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | J 35616 GM Terminal Test Kit |
• | J 44152 Jumper Harness (20 pins) |
Start and idle the engine. Using the scan tool, select PC Solenoid under the Transmission Output Controls. With the scan tool, command several values of solenoid reference current from 0.1-1.1 amps and observe the PC Sol. Actual Current and the PC Sol. Ref. Current. The PC Sol. Actual Current should not vary from the PC Sol. Ref. Current by greater than 0.16 amp.
⇒ | If the resistance is greater than 7 ohms, test the PC Solenoid high control circuit or the PC solenoid low control circuit for an open or a faulty PC solenoid valve. If the resistance is less than 3 ohms, test for the PC solenoid high control circuit and the PC solenoid low control circuit shorted together of a faulty PC solenoid valve. |
⇒ | If the resistance is less than 10K ohms, replace the automatic transmission wiring harness assembly. |
⇒ | If the resistance is less than 10K ohms, replace the automatic transmission wiring harness assembly. |
⇒ | If the value is greater than 10 ohms repair the open in the affected circuit. |
⇒ | If the value is less than 10K ohms repair the short to ground in the affected circuit. |
⇒ | If a short to voltage condition is found, repair as necessary. |
Verify the PC solenoid valve resistance is between 3-7 ohms.
⇒ | If the resistance is not within the specified range, replace the PC solenoid valve. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for TCM replacement, setup, and programming. |