Skip the auto shop - Our mechanics make house calls

Q: Is my problem my ECM relay?

asked by on

My truck sometimes allow me to get to my destination but once there and ready to leave it will not crank. I've had to wait up to 1 hour before or maybe even 5 mins and it cranks up. While headed to the dealership it completely turned off on the highway. I had to have it towed home and now the battery is dead from trying to crank it.
My car's transmission is unknown to me.

A: Hello and thank you for contacting YourMech...

Hello and thank you for contacting YourMechanic. First you will need to charge or replace your battery. Most of the time, if a battery has a burned cell or will not hold a charge, then it causes a lot of errors within the electronics of a vehicle.

Once you have a good battery, test drive the vehicle to see if any problems come back. If the problems come back, then check the wires to the battery and to the main fuse box to ensure that they are tight. Then check the power and ground wires to the ECM. If all of the wires are good, try wiggling the ignition switch to see if you can duplicate the problem without moving the vehicle. If the engine cuts out when moving the key around without turning off the engine, then the ignition switch needs replaced. If not, then the ECM needs replaced. If you need further assistance diagnosing the no start, then have a professional technician, like one from YourMechanic, help you with your vehicle.

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: Ignition issue - 1994 Mitsubishi

This is likely a bad connection problem which is commonly known to cause intermittent non-starting issues like this. Your ignition switch is wired to a harness that eventually runs down to a starter relay which directs power to the starter....

Q: NVIS (Immobilizer System) in my Pathfinder Armada is rejecting my key; I know its correct key.

Operating a modern computer controlled vehicle with a dead battery can damage the Powertrain Control Module due to the voltage instability, particularty voltage excursions on the high side (above 14 volts), that occur when the alternator has no buffer to...

Q: ECM replacement

If you have a need to have the ECM replaced then you will need to have one programmed for your vehicle and have the system integrated so all the modules talk to each other. This will require the computer to...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
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.