P0963
DTC P0963
Circuit Description
The pressure control solenoid (PCS) main modulation (MAIN MOD) is a normally closed (N/C) solenoid used to modulate transmission main pressure. The transmission control module (TCM) commands the solenoid ON when specific transmission and engine conditions are met. When solenoid MAIN MOD is commanded ON, hydraulic pressure is routed to the main pressure regulator valve, lowering transmission main pressure.
The TCM provides voltage to the MAIN MOD, torque converter clutch (TCC) and pressure control solenoid 1 (PCS1) through a separate solid-state device called high side driver 1 (HSD1). The TCM uses a low side driver to switch MAIN MOD ON and OFF.
DTC P0963 is a type A DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0963 Pressure Control Solenoid (PCS) Main Modulation (MAIN MOD) Circuit High
Conditions for Running the DTC
^ The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
^ TCM initialization is in process or engine speed is greater than 200 RPM and less than 7,500 RPM for less than 5 seconds.
^ The TCM must auto-detect the MAIN MOD solenoid for this test to run.
Conditions for Setting the DTC
DTC P0963 sets when the TCM detects a short to voltage in the MAIN MOD solenoid return circuit for greater than 2 seconds.
Action Taken When the DTC Sets
^ The TCM illuminates the malfunction indicator lamp (MIL).
^ DTC P0963 is stored in TCM history.
^ The TCM inhibits MAIN MOD.
Conditions for Clearing the MIL/DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 Warm-up cycles without failure.
Diagnostic Aids
^ Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions:
^ A bent terminal
^ A backed-out terminal
^ A damaged terminal
^ Poor terminal tension
^ A chafed wire
^ A broken wire inside the insulation
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
^ You may have to drive the vehicle in order to experience a condition.
