GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Tracker - 2WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4 Speed-M41 🢒 DTC P2770

Circuit Description

The torque converter clutch (TCC) solenoid engages the lock-up clutch. The powertrain control module (PCM) outputs system voltage in order to turn ON (energize) or remove voltage in order to turn OFF (to de-energize the TCC solenoid). The TCC solenoid controls the hydraulic pressure to the lock-up valve within the transmission. The TCC solenoid remains OFF in the 1st and 2nd gears. The TCC remains ON in the 3rd and 4th gears when the PCM deems appropriate. The TCC solenoid is never ON during 4L operation or when the engine coolant temperature is below 30°C (80°F).

Conditions for Setting the DTC

The voltage detected at PCM connector C3 terminal 8 (2.0L) or terminal 2 (2.5L) is 5.5 volts or higher when the PCM commands the TCC control solenoid OFF.

Action Taken When the DTC Sets
    • DTC P2770 stores.
    • The PCM enters the fail-safe mode.
    • The malfunction indicator lamp (MIL) turns ON.

The torque converter clutch does not engage during fail-safe mode operation.

Diagnostic Aids

Inspect for the following conditions:

    • A shorted TCC solenoid
    • Shorted electrical circuits between the TCC solenoid and the PCM
    • A faulty PCM

The following conditions may cause an intermittent:

    • A reduced connection
    • Rubbed through wire insulation
    • A broken wire inside the insulation

Inspect the PCM harness connectors for the following conditions:

    • Backed out terminals
    • Improper mating
    • Broken locks
    • Improperly formed or damaged terminals
    • Reduced terminal-to-wire connections

If DTC P2770 cannot duplicate, the information included in the Freeze Frame data may be useful in determining the vehicle operating conditions when the DTC set.

Refer to Wiring Repairs in Wiring Systems when repairing any wiring.

DTC Confirmation Procedure
  1. Turn the ignition switch to the LOCK position.
  2. Connect the scan tool to the data link connector (DLC).
  3. Turn the ignition switch ON.
  4. Use the scan tool in order to clear the following items:
    5. • DTC P2770
    • Any pending DTCs
  5. Start the engine.
  6. Apply the brake pedal firmly
  7. Shift the manual selector to DRIVE range.

    8. Remain in DRIVE range for 10 seconds.

  8. Release the brake, then accelerate the vehicle in DRIVE range.

    9. Continue driving for 10 seconds at 30 km/h (20 mph).

    Increase vehicle speed to 80 km/h (50 mph) for 10 seconds .

  9. Stop the vehicle.
  10. Use the scan tool in order to test for a pending DTC.

Test Description

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

  1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. The scan tool creates an electronic copy of the data taken when the fault occurred. The information then stores in the scan tool for later reference.

    2.

  2. This step tests the TCC solenoid circuit for a short to voltage.

    3.

  3. This step tests the TCC solenoid internal coil resistance.

    4.

  4. This step tests shift TCC solenoid circuit for an open.

    5.

  5. This step inspects the condition of the transmission internal electrical harness for damage.

    6.

  6. This step tests for a reduced electrical connection that may have set DTC P2770.

    7.

  7. This step tests for a faulty PCM.

Step

Action

Value(s)

Yes

No

1

Was the On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 2.0L or Diagnostic System Check - Engine Controls in Engine Controls - 2.5L

2
  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 within the Freeze Frame conditions as observed.

Does the scan tool display any other DTCs in addition to DTC P2770?

--

Go to the applicable DTC table

Go to Step 3

3

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the PCM connector C3.
  3. Turn the ignition switch to the ON position.
  4. Use a DMM in order to measure the voltage between ground and the PCM harness connector C3 terminal 8 (2.0L) or terminal 2 (2.5L) .

Is the voltage as specified?

Approximately 0 V

Go to Step 4

Go to Step 10

4

  1. Turn the ignition switch to the LOCK position.
  2. Use a DMM to check for continuity between ground and the PCM harness connector C3 terminal 8 (2.0L) or terminal 2 (2.5L) .

Is the continuity present?

--

Go to Step 7

Go to Step 14

5

Use a DMM to check for continuity between the PCM harness connector C3 terminal 8 (2.0L) or terminal 2 (2.5L) and the transmission solenoid connector terminal 3.

Is the continuity present?

--

Go to Step 6

Go to Step 9

6

  1. Remove the transmission oil pan.
  2. Inspect the terminals and internal harness for damage.
  3. Replace the shift solenoid if no damage exists.

Is the procedure complete?

--

Go to Step 14

--

7

Inspect all of the electrical connections for reduced terminal contact or a reduced connection.

Do reduced terminal contact or reduced connections exist?

--

Go to Step 11

Go to Step 8

8

  1. Install a known good PCM. Refer to Powertrain Control Module Replacement in Engine Controls-2.0L or Powertrain Control Module Replacement in Engine Controls-2.5L.
  2. Perform the DTC Confirmation Procedure.

Does DTC P2770 reset?

--

Go to Step 12

Go to Step 13

9

Repair the open or the high resistance in the TCC solenoid circuit.

Is the repair complete?

--

Go to Step 14

--

10

Repair the short to voltage in the TCC solenoid circuit.

Is the repair complete?

--

Go to Step 14

--

11

Repair any terminals or connections that exhibit reduced contact.

Is the repair complete?

--

Go to Step 14

--

12

Refer to Diagnostic Aids for a possible intermittent condition.

Is the procedure complete?

--

Go to Step 14

--

13

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls-2.0L or Powertrain Control Module Replacement in Engine Controls-2.5L.

Is the procedure complete?

--

Go to Step 14

--

14
  1. Turn the ignition switch to the LOCK position.
  2. Reconnect all the connectors.
  3. Perform the DTC Confirmation Procedure.

Does the scan tool display any DTCs?

--

Go to the applicable DTC table

System OK