Diagnostic Instructions
| • | 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 provides an overview of each diagnostic category. |
DTC Descriptors
DTC P0752: Shift Solenoid (SS) 1 Valve Performance - Stuck OnDTC P0757: Shift Solenoid (SS) 2 Valve Performance - Stuck On
DTC P0762: Shift Solenoid (SS) 3 Valve Performance - Stuck On
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
PS1 Signal | P0752, P0842 | P0751, P0843 | -- | -- |
PS2 Signal | P0757, P0847 | P0756, P0848 | -- | -- |
PS3 Signal | P0762, P0872 | P0761, P0873 | -- | -- |
Typical Scan Tool Data
Display Parameters | Normal Range | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|---|
Operating Conditions: Ignition ON, engine OFF | ||||
TFP Switch 1 | High | Low | High | -- |
TFP Switch 2 | High | Low | High | -- |
TFP Switch 3 | High | Low | High | -- |
Operating Conditions: Engine running, transmission in park or neutral position | ||||
TFP Switch 1 | Low | Low | High | -- |
TFP Switch 2 | Low | Low | High | -- |
TFP Switch 3 | Low | Low | High | -- |
Circuit/System Description
The pressure switch manifold (PSM) is a multiple switch assembly made up of 3 normally open (N/O) pressure switches and 1 normally closed (N/C) pressure switch. Pressure switch 1 (PS1) monitors shift valve 1 positioning, pressure switch 2 (PS2) monitors shift valve 2 positioning, and pressure switch 3 (PS3) monitors shift valve 3 positioning. The pressure switches communicate the positioning to the transmission control module (TCM). The position of the shift valves 1, 2, and 3 is controlled by 3 normally closed shift solenoids 1, 2, and 3 (SS1, SS2, and SS3). When energized, the shift solenoids direct control main pressure to shift valve 1, 2, or 3, which strokes the shift valve.
Conditions for Running the DTC
P0752
| • | Engine Running. |
| • | Shift solenoid 1 (SS1) is commanded OFF. |
P0757
| • | Engine Running. |
| • | Shift solenoid 2 (SS2) is commanded OFF. |
P0762
| • | Engine Running. |
| • | Shift solenoid 3 (SS3) is commanded OFF. |
Conditions for Setting the DTC
P0752
| • | Engine Running. |
| • | SS1 is commanded OFF and PS1 remains ON for up to 11 seconds depending on transmission fluid temperature. |
P0757
| • | Engine Running. |
| • | SS2 is commanded OFF and PS2 remains ON for up to 15 seconds depending on transmission fluid temperature. |
P0762
| • | Engine Running. |
| • | SS3 is commanded OFF and PS3 remains ON for up to 15 seconds depending on transmission fluid temperature. |
Action Taken When the DTC Sets
P0751
| • | The TCM requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
| • | When in a forward range, the transmission will shift to another forward range, unless the transmission is compromised by overspeeding. |
| • | When the shift selector is moved from a forward range to NEUTRAL or from a forward range to REVERSE, then the transmission will shift to NEUTRAL. |
| • | If the shift selector is moved to forward, the transmission will shift to forward and if the selector is moved to REVERSE, the transmission will shift to REVERSE, unless the transmission is compromised by overspeeding or direction change, then a shift to NEUTRAL is made. |
| • | DTC P0752 is stored in TCM history. |
| • | The TCM freezes shift adapts. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
P0757
| • | The TCM requests the ECM to illuminate the MIL. |
| • | When in a forward range and shifting is completed, the transmission will shift to another forward range, unless the transmission is compromised by overspeeding or direction change, then the transmission will shift to NEUTRAL. |
| • | If the shift selector is moved to forward, the transmission will shift to forward and if the selector is moved to REVERSE, the transmission will shift to REVERSE, unless the transmission is compromised by overspeeding or direction change, then a shift to NEUTRAL is made. |
| • | DTC P0757 is stored in TCM history. |
| • | The TCM freezes shift adapts. |
| • | The TCM inhibits TCC engagement. |
P0762
| • | The TCM requests the ECM to illuminate the MIL. |
| • | When in a forward range and shifting is completed, the transmission will shift to another forward range, unless the transmission is compromised by overspeeding or direction change, then the transmission will shift to NEUTRAL. |
| • | When in a forward range and the shift is in process the transmission will return to a previous range, except for 1-2 shifts and 2-1 shifts which will be completed. |
| • | If the shift selector is moved to forward, the transmission will shift to forward and if the selector is moved to REVERSE, the transmission will shift to REVERSE, unless the transmission is compromised by overspeeding or direction change, then a shift to NEUTRAL is made. |
| • | DTC P0762 is stored in TCM history. |
| • | The TCM freezes shift adapts. |
| • | The TCM inhibits TCC engagement. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, command the transmission through the forward ranges with a scan tool. Compare the TFP Switch 1, TFP Switch 2, and TFP Switch 3 parameters in each forward range with the PSM Logic table. Refer to Pressure Switch Manifold (PSM) Logic.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Warning: Chock the wheels to prevent the vehicle from moving. Failure to chock the wheels can cause personal injury when the electrical system is repaired.
Circuit/System Testing
- Ignition ON, engine OFF, verify with a scan tool the TFP Switch 1, TFP Switch 2, and TFP Switch 3 parameters are High.
- Ignition OFF, disconnect the X175 harness connector at the transmission.
- Ignition ON, engine OFF, verify with a scan tool the TFP Switch 1, TFP Switch 2, and TFP Switch 3 parameters are High.
- Remove the transmission oil pan. Refer to Oil Pan Replacement.
- Test the transmission internal Pressure Switch 1, 2, and 3 signal circuits for a short to ground.
Note: You must perform the Circuit/System Testing first.
| ⇒ | If TFP Switch 1, TFP Switch 2, and TFP Switch 3 parameters are the specified value, refer to Control Valve Body Assembly Disassemble and Control Valve Body Cleaning and Inspection. If valve body inspection is normal, replace the shift solenoid indicated by the DTC, refer to Control Valve Solenoid Replacement. |
| ⇒ | If not the specified value, test the affected pressure switch signal circuit for a short to ground. If circuits tests normal, replace the TCM. |
| ⇒ | If the circuits test normal, replace the PSM. Refer to Pressure Switch Manifold Replacement. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for TCM replacement, setup, and programming |
Repair Verification
If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
