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 Descriptor
DTC P2727: Pressure Control (PC) Solenoid 1 OpenDTC P2729: Pressure Control (PC) Solenoid 1 Control Circuit Low Voltage
DTC P2730: Pressure Control (PC) Solenoid 1 Control Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Control | P2729 | P2727 | P2730 | -- |
Circuit/System Description
The Pressure Control Solenoid 1 (PCS1) is a solenoid that controls pressure which is proportional to the current. The transmission fluid pressure from PCS1 is directed to another valve which regulates the transmission fluid flow and pressure through shift valves that allows it to engage different clutches.
The transmission control module (TCM) provides B+ to PCS1, the torque converter clutch (TCC) solenoid, and the main modulation/line pressure control solenoid (MAIN MOD) through a separate solid state device called high side driver 1 (HSD1). The TCM uses a low side driver to control the current flow to the PCS1. The TCM controls the current to the solenoid by changing the amount of time that the low side driver is on.
Conditions for Running the DTC
| • | No DTCs P0657, P0658, or P0659. |
| • | Battery voltage is greater than 9.0 V and less than 18 V. |
| • | Engine speed is greater than 200 RPM. |
| • | Engine crank time is not extended. |
Conditions for Setting the DTC
P2727
This DTC sets when the TCM detects an open circuit on the PCS1 control circuit for greater than 1 second.
P2729
This DTC sets when the TCM detects a short to ground on the PCS1 control circuit for greater than 1 second.
P2730
This DTC sets when the TCM detects a short to voltage on the PCS1 circuit for greater than 1 second.
Action Taken When the DTC Sets
| • | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL). |
| • | If the fault 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 P2727, P2729, or P2730 is stored in TCM history. |
Conditions for Clearing the DTC
DTCs P2727, P2729, and P2730 are Type A DTCs.
Diagnostic Aids
P2727
| • | You may have to drive the vehicle in order to experience a condition. |
| • | If DTC P2727 is accompanied by DTC P0960, MAIN MOD open circuit, and/or DTC P2761, TCC open circuit, the open is most likely in the HSD1 circuit. |
P2729 and P2730
You may have to drive the vehicle in order to experience a condition.
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
- Ignition ON, engine OFF, command the PC Solenoid 1 ON and OFF with a scan tool. Observe the operation of the PC Sol. 1 Pressure Command parameter. The PC Sol. 1 Pressure Command parameter should change from 0 kpa (0 psi) to 1600 kpa (232 psi).
- 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.
Circuit/System Testing
- Ignition OFF, disconnect the X175 harness connector at the transmission.
- Ignition ON, engine OFF, verify that a test lamp illuminates between the B+ circuit terminal L and ground.
- Connect a test lamp between the control circuit terminal M and the B+ circuit terminal L.
- Command the PC Solenoid 1 ON and OFF with a scan tool and verify the PC Sol. 1 Pressure Command parameter changes from 1600 kPa (232 psi) to 0 kPa (0 psi). The test lamp should turn ON and OFF when changing between the commanded states.
- Remove the transmission oil pan. Refer to Oil Pan Replacement.
- Test the transmission internal PCS1, B+, and control circuits for a short to voltage, short to ground, or an open/high resistance.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TCM. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the TCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the TCM. |
| ⇒ | If the circuits test normal, test or replace the PCS1 solenoid. |
Component Testing
Static Testing
- Ignition OFF, remove the PCS1 solenoid from the valve body. Refer to Control Valve Solenoid Replacement.
- Test for resistance between the control circuit terminal 2 and the B+ circuit terminal 1 of the PCS1. Refer to Temperature Versus Resistance.
Note: You must perform the Circuit/System Testing first.
| ⇒ | If not within the specified range, replace the PCS1 solenoid. |
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.
