Circuit Description
The pressure control solenoid 1 (PCS1) 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 main modulation (MAIN MOD), torque converter clutch (TCC) and PCS1 through a separate solid-state device called high side driver 1 (HSD1). The TCM regulates the amount of current to the PCS1 by switching the low side driver ON and OFF.
DTC P2727 is a type A DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2727 Pressure Control Solenoid 1 (PCS1) Control Circuit Open (A)
Conditions for Running the DTC
| • | DTC P0658 and P0659 are not active. |
| • | The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts. |
| • | Engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds. |
| • | TCM initialization is in process. |
| • | Engine crank time is not extended. |
Conditions for Setting the DTC
DTC P2727 sets when the TCM detects an open circuit on the PCS1 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 P2727 is stored in TCM history. |
| • | The TCM inhibits MAIN MOD. |
| • | 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 resistance reading within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
4 |
Is the resistance within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Step 6 | Go to Step 5 |
5 |
Is the solenoid resistance within the specified value? | 5.05 ohms at 20°C (68°F) | Go to Step 7 | Go to Step 8 |
6 | Test the PCS1 circuit between the TCM and the AT inline 20-way connector for an open condition. Refer to Testing for Continuity . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
7 | Replace the AT internal wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
8 | Replace the PCS1. Refer to Control Valve Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
9 |
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 10 | -- |
10 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 11 | Go to Step 2 |
11 | 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 | |
