Circuit Description
The pressure control solenoid 2 (PCS2) is a pressure proportional to current (PCC) solenoid used to control on-coming, off-going and holding pressure to any 1 of the 5 clutches. The transmission control module (TCM) provides voltage to the PCS2, shift solenoid 1, 2, and 3 (SS1, SS2, and SS3) through a separate solid-state device called high side driver 2 (HSD2). The TCM regulates the amount of current to the PCS2 by switching the low side driver ON and OFF.
DTC P0966 is a type A DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0966 Pressure Control Solenoid 2 (PCS2) Control Circuit Low (B)
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 5 seconds. |
| • | Engine crank time is not extended. |
| • | Associated HSD2 is enabled and no HSD2 codes are active. |
Conditions for Setting the DTC
DTC P0966 sets when the TCM detects a short to ground on the PCS2 circuit for greater than 2 seconds.
Action Taken When the DTC Sets
| • | The TCM illuminates the malfunction indicator lamp (MIL). |
| • | If the failure occurs while in a forward range, a shift to 1st, 3rd or 5th range is made. |
| • | While diagnostic response is active, if the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL. If the shift selector is moved to REVERSE, the transmission will shift to REVERSE. If the shift selector is moved to a forward range or to REVERSE and the transmission is compromised by overspeeding or direction change, the transmission will shift to NEUTRAL. |
| • | DTC P0966 is stored in TCM history. |
| • | Main modulation (MAIN MOD) is inhibited. |
| • | The TCM freezes shift adapts. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
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. |
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Is voltage within the specified value? | 9-18 V | Go to Step 3 | Go to DTC P0562 for low voltage or DTC P0563 for high voltage |
3 |
Is the voltage within the specified value when the PCS2 is commanded OFF? | B+ | Go to Diagnostic Aids | Go to Step 4 |
4 |
Is the resistance reading within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Step 10 | Go to Step 5 |
5 |
Is the resistance within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Step 7 | Go to Step 6 |
6 |
Is the solenoid resistance within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Step 8 | Go to Step 9 |
7 | Test the PCS2 circuit between the TCM and the AT inline 20-way connector for a short to ground condition. Refer to Testing for Short to Ground . Did you find and correct the condition? | -- | Go to Step 11 | -- |
8 | Replace the AT internal wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
9 | Replace the PCS2. Refer to Control Valve Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 |
Important: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 12 | Go to Step 2 |
12 | 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? | -- | System OK | |
