Q: My car won't start back up after idling and won't read codes

With the car idling for an extended period, your engine compartment will get extra hot and this may cause the ignition module to fail, resulting in a stalled engine that will not restart. In order to determine whether the ignition module has failed or another ignition component is at fault, you will need to check to see if your coil is giving out a strong spark. If you are not getting any spark, then the coil wires will need to be tested. Check to see if the coil is getting power on the red wire with the key in the on position, and then check for a pulsing power on the green wire using a test light. If you are not getting any spark out of the coil, but do have pulse power to the coil’s green wire when the vehicle is cranked, then you will need to replace the ignition coil. If there is not any pulse power getting to the coil, then you will need to replace the ignition module. If you still cannot determine which component is at fault, then contact a mobile mechanic, like one from YourMechanic, to continue the diagnosis of your no start condition.