Skip the auto shop - Our mechanics make house calls

Q: I can't get the car to turn over

asked by on

It like there no when you try to turn it over theres nothing i have all the dash lites working and iv change the starter put a different computer on it and I don't have fuel pressure either
My car has an automatic transmission.

A: To start, computers, aka PCM (powertrain co...

To start, computers, aka PCM (powertrain control modules) rarely fail. They are complex units that require many different inputs to initiate the desired response. Having replaced your PCM already, you may have already traded in your old PCM as a core. If you happen to still have it, I would plug it back in and continue by doing some testing at the starter relay. From the relay you can check to see if it is the PCM that isn’t commanding the relay to supply power to the starter ored if there is something else wrong.

It is possible the relay is the source of the problem. You will need a wiring diagram and then you can use a jumper wire to supply power to the starter solenoid from the relay connector. If the starter turns over, you have confirmed that this part of the starter system is good.

Having replaced the PCM, this is likely the cause of the lack of fuel pressure. As far as why it won’t crank, you have complicated the issue by replacing the PCM. The new PCM needs to be programmed using a professional scan tool. If you have already done this, then you can begin diagnosing the no crank, assuming the PCM has been successfully programmed.

If you should still need help with this diagnosis, I recommend the following inspection to help you out. A certified professional from YourMechanic can come to your car’s location to diagnose the starting issue and assist with repairs.

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

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: No power to dash when you turn key but will crank.

Check for "codes" (PCM, ECU, BCM) to see if any read out. If no codes, this is a switch (ignition), fuse, relay, and/or wiring problem which has to be tracked down systematically.

Q: Bad transmission 2003 Chevrolet Impala

Hi - first thing to check if for correct fluid level in the transmission. Having too much fluid will cause foaming, fluid being forced out the transmission dipstick/filler tube and other behavioral issues. It is also possible, given your mileage,...

Q: loss of power. 2003 Mazda 6

Hi there, thanks for writing in. You should check to see if the timing belt is off or jumped, or your injectors have some blockage and needs to be cleaned cleaned. Also, make sure you have a clean fuel filter....

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...
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.