GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Optra 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P2757

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2757

Conditions for Running the DTC

When the Emergency mode is ON, the following conditions occur :

    • Throttle is 10 percent or greater.
    • Shift position is D, M, 2 range.
    • 0.5 second pass after shifting control.
    • Engine speed is 4,000 RPM or less.
    • No shifting.
    • System voltage is greater than 10.5 volts.
    • TCC PC solenoid reference current is 1A or greater.
    • Lock up is ON.
    • Emergency mode is OFF.
    • No failure detection of output speed sensor, input speed sensor, selector position, shift solenoid, linear solenoid, CAN BUS OFF, engine RPM, engine torque, throttle, transmission fluid temperature sensor.
    • No failure detection of ABS and wheel speed.

Conditions for Setting the DTC

Engine RPM - input speed RPM is greater than 100 RPM for 12 seconds.

Action Taken When the DTC Sets

    • TCM will request the illumination of MIL.
    • TCM records the operating condition when the Conditions for Setting the DTC are met. TCM stores this information as Failure Record.
    • TCM stores DTC in TCM history.
    • TCM turns Emergency mode ON.
    • The transmission will operate in 4th gear when the transmission is shifted into D or M+ range.
    • The transmission will operate in 2nd gear when the transmission is shifted into 2 or M- range.
    • Learn control is disabled.
    • Lock up control is disabled.
    • Adaptive control is disabled.
    • N-D shifting is disabled.
    • ABS function is disabled.

Conditions for Clearing the MIL/DTC

    • The MIL turns OFF when no failure is detected for three consecutive driving cycles.
    • The scan tool can clear the DTC from the TCM history.
    • TCM clears the DTC from the TCM history memory after forty consecutive warm-up cycles without fault.

Cause of Failure

    • Shift Solenoid (SS) 4 (Stuck OFF)
    • TCC Lock Up Pressure Control (PC) Solenoid (ON/OFF Stuck)
    • Lock Up Clutch Failure
    • Inside Valve Body
    • TCM

Step

Action

Values

Yes

No

1
  1. Turn the ignition OFF.
  2. Install the Scan tool.
  3. With the engine OFF, turn the ignition switch to the ON position.
  4. Select Store Freeze Frame/Failure Records from the Diagnostic Trouble Codes Information menu.
  5. Store Freeze Frame/Failure Records.
  6. Select Clear DTC Information from the Diagnostic Trouble Codes Information menu.
  7. Clear DTC Information.
  8. Perform one vehicle drive cycle.

Is the Malfunction Indicator Lamp (MIL) ON?

--

Go to Step 2

Repair the temporary connection failure of connector. Refer to Repairing Connector Terminals.

2
  1. Select Request DTC by Status from the Diagnostic Trouble Codes Information menu.
  2. Request DTC by Status.

Is DTC P2757 displayed?

--

Go to Step 3

Repair the temporary connection failure of connector. Refer to Repairing Connector Terminals.

3
  1. Turn the ignition OFF.
  2. Replace the master TCM and perform simulation test again under user condition.

Is DTC P2757 reappeared?

--

Go to Step 4

Replace the TCM.

4
  1. Estimate the failure of shift solenoid (SS) 4, TCC lock up pressure control solenoid, lock up clutch or shift solenoid (SS) 4.
  2. Inspect SS4.

Is the condition of the solenoid OK?

--

Go to Step 5

Replace SS4

5

Estimate the failure of TCC lock up pressure control solenoid or internal valve body.

Is problem found?

--

Replace the valve body assembly. Refer to Control Valve Body Replacement

Repair or Replace the transaxle assembly. Refer to Transmission Replacement