GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 Vibe - AWD 🢒 DTC 🢒 DTC P0770

Circuit Description

The powertrain control module (PCM) uses signals from the vehicle speed sensor to detect torque converter clutch (TCC) lock-up status. The PCM then compares the actual data with the TCC lock-up schedule in the PCM memory to detect mechanical trouble of the TCC solenoid and valve body.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0770 Torque Converter Clutch (TCC) System Performance

Conditions for Setting the DTC

DTC P0770 will set when one of the following conditions are met:

    • TCC lock-up does not occur after the PCM commands the TCC to apply.
    • TCC remains locked-up even after the PCM commands the TCC to release.

Action Taken When the DTC Sets

A DTC P0770 is stored and the malfunction indicator lamp (MIL) is turned ON.

Diagnostic Aids

Inspect for the following conditions:

    • Clogged or leaky TCC solenoid
    • Valve body fluid passage clogged
    • Torque converter clutch malfunction
    • Faulty PCM

If this DTC cannot be duplicated, the information included in the freeze frame data can be useful in determining vehicle operating conditions when the DTC was first set.

DTC Confirmation Procedure
  1. Turn the ignition switch to LOCK.
  2. Connect the scan tool to data link connector (DLC).
  3. Turn the ignition switch to ON.
  4. Clear the DTC, the pending DTC, and the freeze frame data in PCM memory by using the scan tool.
  5. Start the engine and warm up to normal operating temperature.
  6. Use the scan tool to monitor the operation of the TCC solenoid.
  7. Accelerate vehicle in Drive (D) range and drive at 80 km/h (50 mph) for 10 seconds.
  8. Stop the vehicle.
  9. Test for a pending DTC with the scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The Diagnostic System Check - Vehicle, prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

  2. This step checks for proper shift points.

    3.

  3. This step checks for a stuck closed lock-up solenoid.

    4.

  4. This step checks for a leaky lock-up solenoid.

    5.

  5. This step checks the condition of the valve body assembly.

    6.

  6. This step checks for a faulty PCM.

Step

Action

Yes

No

1

Did you preform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Does the scan tool display any other DTCs?

Go to applicable DTC table

Go to Step 3

3
  1. Install a scan tool.
  2. Turn the ignition to ON, leaving the engine OFF.
  3. Perform the scan tool Clear DTC Information function.
  4. Operate the vehicle with the scan tool connected.

Did DTC P0770 reset?

Go to Step 4

Go to Diagnostic Aids

4

Perform the Upshifts and Torque Converter Clutch Apply Procedure in Road Test in order to diagnose the mechanical condition of the transaxle.

Was a mechanical failure detected?

Go to Step 11

Go to Step 5

5

  1. Apply 12 volts to the shift lock-up solenoid (positive to wire, negative to case).
  2. Apply 490 kPa (71 psi) of compressed air into shift solenoid inlet.

Did the lock-up solenoid outlet port open and did air escape?

Go to Step 10

Go to Step 6

6

  1. Remove the lock-up solenoid.
  2. Apply 490 kPa (71 psi) of compressed air into the lock-up solenoid inlet port.

Did the lock-up solenoid outlet port stay closed and did no air leak?

Go to Step 10

Go to Step 7

7

Remove valve body and inspect its passages for any obstructions/restrictions. Refer to Solenoids and Wiring Harness Replacement .

Is the valve body in good condition?

Go to Step 8

Go to Step 9

8

  1. Install a known good powertrain control module (PCM). Refer to Powertrain Control Module Programming and Setup in Programming and Setup.
  2. Perform the DTC Confirmation Procedure.

Does this DTC reset?

Go to Step 11

Go to Step 12

9

Repair or overhaul valve body assembly.

Is the action complete?

Go to Step 13

--

10

Replace the lock-up solenoid.

Is the action complete?

Go to Step 13

--

11

Refer to Road Test for further diagnosis of the transaxle performance. Repair as necessary.

Is the action complete?

Go to Step 13

--

12

Replace PCM. Refer to Powertrain Control Module Programming and Setup in Programming and Setup.

Is the action complete?

Go to Step 13

--

13

Observe the Capture Info with the scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK