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Q: Hesitation, sputtering and check engine light flickering

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My car has hesitation issues. It accelerates from the dead stop, which is followed by hesitating for a few seconds. Then, the car returns to normal. This started happening a few months ago. While idling at a stop light the other day, the car stalled so I restarted it. Then, it worked normally for 15 minutes. The vehicle stalled again while I was driving at 65 mph on the highway. When I stopped the truck, I noticed that there was no RPM indication, while it was vibrating and sputtering. There was also problems with the check engine light, which went on and off, flickering. The vehicle gave no codes. Do you have any suggestions about what might cause this?

A: The problems you are having may be the elec...

The problems you are having may be the electrical harness intermittently loosing contact with the engine control module (ECM). The ECM may be loosing power intermittently from the main power supply. This is not a common issue; a qualified mechanic should perform a thorough check - "a wiggle test" - of each and every harness to see which harness is causing the loss of connection to the ECM. A connector may have corrosion in it and a wiggle test with the engine running should be done before disconnecting the connectors.

Once the faulty connector is found then the connector can be removed and checked for corrosion or broken wires. It may take a mechanic a while to find and fix the problem for you through a thorough diagnostic of the sputtering issue.

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