Skip the auto shop - Our mechanics make house calls

Q: Automatic transmission not shifting properly.

asked by on

My automatic transmission will only shift into reverse or first gear.

A: The computer on these cars are prone to int...

The computer on these cars are prone to interference if the owner has put on an aftermarket code scanner to the ALDL connector to scan the computer. Some owners use these to monitor system functions or for other reasons. These aftermarket testers have been known to cause many problems with the computer or components in the car like transmission, ABS, Engine and other items that require use of the communication lines that this aftermarket tester also uses. Try to remove the tester and restart the engine and road test for problem to be fixed. I recommend to have a qualified mechanic check it out such as one from YourMechanic.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Won't engage gears 1994 Ford F250 4WD

Hi - for your "no movement problem" I would first check fuses for the transmission and 4WD controller. Then check the electrical wiring connections both to the transmission and to the 4WD controller. Perhaps the vibration of the railroad crossing...

Q: Car will not start - Chevrolet Monte Carlo

If what you are doing with your key fob is indeed affecting your cars ability to start, I would have to point you in the direction of the security system. Aside from your security system, your key fob itself will...

Q: Cold start?

Hi there. Ambient temperature can affect any number of electrical components. There could be a poor electrical connection in the power distribution center. The fact that the check engine light is not coming on once the engine does start leads...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...