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

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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.

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

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.

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