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For 1990-2009 cars only
Makes 🢒 Holden 🢒 2005 🢒 Commodore Executive 🢒 DTC 🢒 DTC P0756

DTC P0756 V6

DTC Description

This diagnostic procedure supports DTC P0756 2-3 Shift Solenoid (SS) Valve Performance -- No First of Second Gear.

Circuit Description

The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 valve is a normally-open exhaust valve that is used with the 1-2 SS valve, on order to allow four different shifting combinations.

When the transmission control module (TCM) detects a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a type A DTC.

Refer to Automatic Transmission Controls Schematics , Automatic Transmission Inline 20-Way Connector End View, Automatic Transmission Internal Connector End Views , Automatic Transmission Control Module Connector End Views , and Automatic Transmission Related Connector End Views to aid in diagnosis.

Conditions for Running the DTC
    • No DTCs P0120, P0722, P0723, P0742, P0973, P0974, P0976, P0977 or P1815
    • The engine torque is 108-882 N·m.
    • The engine run time is greater than 5 seconds.
    • The transmission fluid temperature is 20-130°C.
    • The throttle position is greater than 10 percent.
    • The output shaft speed is greater than 150 RPM.

Conditions for Setting the DTC

Both of the following conditions must occur twice during the same trip:

    • Fail Case 1: The TCM commands 1st gear when the output shaft speed is 200 RPM. or greater, the engine torque is 40-350 N·m, and the resulting gear ratio is 0.73:1-0.77:1 for 2.8 seconds.
    • Fail Case 2: The TCM commands 2nd gear when the engine torque is 36-350 N·m and the resulting gear ratio is 1.56:1-1.64:1 for 1 second.

Action Taken When the DTC Sets
    • The TCM requests the ECM to illuminate the check powertrain icon during the second consecutive trip in which the conditions for setting the DTC are met.
    • The TCM inhibits 1st gear.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are met. The TCM stores this information as a Failure Record.
    • At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC are met. The ECM stores this information as a Freeze Frame.
    • The TCM stores DTC P0756 in TCM history.

Conditions for Clearing the DTC
    • The ECM turns off the check powertrain icon after the fourth consecutive drive trip in which the TCM does not send a check powertrain icon illumination request.
    • Tech 2 can clear the DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
    • The TCM cancels the DTC default actions when the ignition is off long enough in order to power down the TCM.

Diagnostic Aids
    • If you clear DTC P0756, and then cannot reset DTCP0756, the following conditions may exist:
       - Fluid contamination,
       - Blocked fluid circuits, or
       - Restricted fluid circuits.
    • Refer to Shift Solenoid Valve State and Gear Ratio.

Test Description

The following numbers refer to the step numbers on the diagnostic table:

2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.

3 Checks the mechanical components that cause the DTC and their state.

Step

Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to Diagnostic System Check - Automatic Transmission

2
  1. Connect Tech 2 to the DLC.
  2. Turn on the ignition, with the engine off.

    3. Important: Before clearing the DTC, use the Tech 2 Freeze Frame/Failure Record in order to record the transmission parameters at the time the DTC set. Using Tech 2 to clear the DTC(s) erases the Freeze Frame/Failure Record records from the TCM.

  3. On Tech 2 select:

    4. Transmission / Automatic Transmission / Diagnostic Trouble Codes / Freeze Frame.

  4. Select the relevant DTC and note the parameters at the time of the DTC setting.
  5. On Tech 2 select:

    6. Diagnostic Trouble Codes / Clear Engine and Transmission DTCs.

  6. Follow the instructions on Tech 2 and clear the DTCs.
  7. Drive the vehicle in D4 range under the following conditions:
    8. • Accelerate the vehicle, and
    • Ensure the TCM commands 1st, 2nd, 3rd and 4th gears.

Did you detect a 4-3-3-4 shift pattern?

Go to Step 3

Refer to Diagnostic Aids within this Section

3
  1. Inspect the shift solenoid/hydraulic circuit for the following conditions:
    2. • Debris or chips in the AFL oil passage.
    • Debris or chips restricting oil flow in passage #29 of the case or through the space plate gasket into the valve body.
    • A cracked 2-3 shift solenoid.
    • A 2-3 shift valve which is stuck or hung up in the valve body bore.
    • A 2-3 shuttle valve which is stuck or hung up in its bore.
    • Damaged seals on the shift solenoid valves. Perform the shift solenoid leak test, refer to Shift Solenoid Leak Test.
  2. Clean and inspect the related valves, bores and the valve body for debris or contamination.

Did you find and correct the condition?

Go to Step 4

--

4

Perform the following procedure in order to verify the repair:

  1. On Tech 2 select:

    2. Diagnostic Trouble Codes / Clear Engine & Transmission DTCs

  2. Follow the instructions on Tech 2 and clear any DTCs.
  3. Drive the vehicle in D4 range under the following conditions, only if traffic and road conditions permit:
    4. • Hold the throttle at 40%, and
    • Accelerate to 64 km/h.
  4. On Tech 2 select:

    5. Diagnostic Trouble Codes / Read DTC Information.

Has DTC P0756 set?

Go to Step 2

Go to Step 5

5

On Tech 2 select:

Diagnostic Trouble Codes / Read DTC Information.

Does Tech 2 display any DTCs you have not diagnosed?

Refer to Diagnostic Trouble Code (DTC) List/Type

System OK

When all diagnosis and repairs are completed, check the system for correct operation.