Skip the auto shop - Our mechanics make house calls

Q: Error 100 reading on the odometer. Battery fuses and starter are all good. My car won't crank.

asked by on

Car won't crank replaced battery checked all fuses and AutoZone checked starter when my boyfriend did diagnosed it read error 100 radio and power is good? Please help

My car has 183000 miles.
My car has an automatic transmission.

Hello and thank you for contacting YourMechanic. Check the engine control module (ECM) for an open short to ground. Check the battery’s positive voltage input circuits, the battery positive voltage output circuits, the ignition voltage input circuits, the ignition voltage output circuits, and the switched battery positive voltage circuits. If any of the circuits are not showing any voltage reference, then replace the ECM. If you need assistance troubleshooting your vehicle, then seek out a professional, such as one from YourMechanic, in order to diagnose the cranking problem and proceed with the appropriate repair.

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!
  1. Home
  2. Questions
  3. Error 100 reading on the odometer. Battery fuses and starter are all good. My car won't crank.

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: Brakes hard to press

If this is not related to any vacuum leaks, the next place to check would be the brake booster itself. As you press the brake pedal down, a shaft inside the brake booster moves forward into a diaphragm, which separates...

Q: I'm going to go look at a 2008 g6 soon and the crankshaft position sensor is out what kind of problems can it cause?

If the crankshaft position sensor has totally failed, the vehicle may not start which of course will make it very difficult to evaluate whether the car is a wise choice. The car should be running before you buy it, otherwise...

Q: I hear a growling sound coming from the front driver side. I believe it's the bearing. Should I consider repacking or replacing?

Hello, the noise you hear could be a front hub bearing. The hub bearing is serviced as a complete unit assembly. If you'd like, a certified Your Mechanic Technician can come to your location to inspect this noise. Please look...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...