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P0742 GMC Code - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance

- Code Popularity: 17,074 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0742 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Low transmission fluid level
  • Dirty transmission fluid
  • Faulty Control Solenoid Valve Assembly
  • Control Solenoid Valve Assembly harness is open or shorted
  • Control Solenoid Valve Assembly circuit poor electrical connection
  • Transmission internal mechanical problem
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How to Fix the DTC P0742 GMC?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

When a transmission solenoid is stuck on, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommended to change the transmission fluid and if possible, remove the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure, and that the transmission will need to be rebuilt or replaced.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0742 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0742 GMC Description

The Torque Converter Clutch (TCC) pressure control solenoid is part of the control solenoid valve assembly which has no serviceable parts. The TCC pressure control solenoid is a normally low-pressure control solenoid. The TCC pressure control solenoid regulates the transmission fluid to the TCC regulator valve in the lower valve body and the TCC control valve in the pump cover. When vehicle operating conditions are appropriate to apply the converter clutch, the Transmission Control Module (TCM) will increase TCC pressure control current flow (duty cycle) to the TCC solenoid. The TCC pressure control solenoid directs fluid pressure to move the TCC control valve to the apply position and moves the TCC regulator apply valve to the regulating position. The TCC regulator valve regulates TCC apply fluid pressure proportional to TCC solenoid pressure. When the TCC is fully applied, the engine is coupled directly to the transmission. TCC release is accomplished by the Transmission Control Module decreasing current flow to the TCC pressure control solenoid. This results in decreasing the applied pressure which allows the TCC control valve to move to the release position. The Transmission Control Module calculates torque converter slip speed based on engine speed and transmission input shaft speed.
The Diagnostic Trouble Code (DTC) will be set when the CM detects the TCC slip between −50 and +13 RPM for 6 s when the TCC is commanded OFF.

OBDII Code P0742 GMC - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance - AutoCodes.com
P0742 GMC Code - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance

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Code P0742 GMC comments

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