GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Holden 🢒 2008 🢒 Viva 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0742

Circuit Description

Shifting between individual gears takes place by means of overlapping clutch engagement and release.

If 2 clutches are engaged or released at the same time during shifting, the transaxle or engine could be damaged.

To prevent this damage, the transmission control module (TCM) monitors the clutch pressure at the shifting point.

Once shifting begins, the TCM begins the monitoring after the regular time and inspects the turbine revolution speed. If the revolution speed is not within the specified value, the fault occurs and the TCM memorizes it.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0742 Torque Converter Clutch (TCC) System - Stuck On

Conditions for Setting the DTC
    • The vehicle shift solenoid fault does not occur.
    • The throttle is more than 25 percent.
    • The transmission oil temperature is more than -10°C (+14°F).
    • The system voltage is more than 9 volts.
    • No input speed error DTCs P0715, P0716, and P0727 are set.
    • No engine speed error DTCs P0725, P0726, and P0727 are set.
    • The engine speed is more than 1,200 RPM.
    • The input speed is more than 1,200 RPM and 3,500 RPM.
    • The engine is running.
    • The selector lever is not in the Neutral (N) or Park (P) position.
    • The torque converter clutch (TCC) lock-up status is commanded OFF.

Action Taken When the DTC Sets
    • The malfunction indicator lamp (MIL) will illuminate.
    • The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
    • Open the lock-up clutch.

Conditions for Clearing the MIL/DTC
    • The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.
    • A history DTC will clear after 40 consecutive warm-up cycles without a fault.
    • Using a scan tool can clear history DTCs.

Diagnostic Aids
    • Inspect the poor wiring harness connection for TCM connectors and transaxle wiring connectors.
    • Inspect the improperly formed or damaged terminals.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2
  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select Actuating on the scan tool.
  4. Actuate the pressure control solenoid (PCS) ON/OFF.

Does the PCS change ON/OFF?

--

Go to Diagnostic Aids

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the transaxle wiring connector.
  3. Measure the resistance between terminals 5 and 6 of the transaxle wiring connector.

Is the resistance within the specified value?

6 ohms

Go to Step 5

Go to Step 4

4
  1. Remove the oil pan.
  2. Disconnect the wiring connector of the PCS 3.
  3. Replace the PCS 3.

Is the action complete?

--

System OK

--

5
  1. Disconnect the transaxle wiring connector.
  2. Remove the oil pan.
  3. Replace the valve body. Refer to Control Valve Body Replacement .

Is the action complete?

--

Go to Step 6

--

6
  1. After the repair, use a scan tool Clear Info function and road test the vehicle.
  2. Review the DTC Info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 1

System OK