Skip the auto shop - Our mechanics make house calls

Q: Sometimes my car will not shift into overdrive and then sometimes it does, any idea what could be causing this?

asked by on

I have noticed while driving my tercel that sometimes it will shift into overdrive and othertimes it will not. There is no check engine light on in the car and the transmission shifts great in 1, 2, 3. I have no idea what could be causing this problem or where to start.

My car has 238000 miles.
My car has an automatic transmission.

This symptom is the TCC (Torque Converter Clutch) is slipping in and out while driving. To check this condition, scan the computer to see whether the TCC action is being commanded by the computer. There could be a problem with the throttle position sensor (TPS) on the throttle body causing the engine to rev up and down to make the TCC disengage and engage. If there is no issue with the TPS, then the TCC valve in the valve body (brain of the transmission) inside the transmission has made its bore larger than the valve and causing an internal leak making the valve buzz back and forth. This action will cause the TCC to engage and disengage multiple times as long as the TCC is to be engaged. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  • Home
  • Questions
  • Sometimes my car will not shift into overdrive and then sometimes it does, any idea what could be causing this?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Fuel pump just clicks once not running

The fuel pump is going to be the most common cause of the loss of fuel pressure. I recommend having the fuel pump replaced. The fuel system and pressures should be completely checked prior to replacing the pump. I recommend...

Q: Lost my key and have to start car with ignition switch but my steering column is locked how do I unlock it

Hi there. Unfortunately, without seeing what repairs were made and how the ignition switch was installed, it's hard to give you advice on how to get the steering column unstuck. You might want to have one of our mobile mechanics...

Q: Car not starting

This is a common problem. Although no start conditions can be caused by many things, there are two common issues that come to mind, starter failure and a parasitic drain. Often times when a starter fails it simply does nothing...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.