Error code

OBD2 P0740

OBD2P0740
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Torque Converter Clutch Circuit/Open.

Severity

highDriving may be possible but harsh shifting and slippage can cause further damage.

Summary

P0740 indicates an issue with the Torque Converter Clutch (TCC) solenoid circuit malfunction in the transmission control system.

Symptoms

  • Malfunction Indicator Lamp (MIL) lights up
  • Torque converter clutch does not engage or disengage properly
  • Disabled shifting function causing engine stall when stopping
  • Harsh shifting, slippage, overheating of the transmission

Common Causes

  • Low, dirty, or contaminated transmission fluid
  • Excessive debris or metal particles in the transmission pan
  • Defective pressure control solenoid
  • Open or shorted line pressure solenoid valve harness
  • Poor electrical connection to the line pressure solenoid valve circuit
  • Fluid blockages inside the transmission passages
  • Mechanical internal transmission failures

Diagnosis

  1. Check for DTCs under chassis and body systems as well as powertrain codes.
  2. Inspect transmission fluid condition and level.
  3. Remove the transmission pan to check for debris or metal particles.
  4. Test electrical connections and harnesses related to the TCC solenoid.

Fixes

  • Replace defective pressure control solenoid

FAQ

What should I do if my MIL lights up with P0740?

Check the transmission fluid condition and inspect for debris. Test electrical connections related to the TCC solenoid.

Is it safe to drive with a P0740 code?

Driving may be possible but harsh shifting and slippage can cause further damage, so it's recommended to address the issue promptly.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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