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Q: CEL transmission slipping

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My truck is a carpet cleaning truck. And I am not sure if my equipment has anything to do with the problems I am having. But I have been getting this code: P2534 - ignition 1 switch circuit low voltage - off and on for months. When I am driving 45 mph my engine was at 2900 rpms. Is that second gear? I had not used my carpet cleaning equipment after the code was cleared the last time. When I drove up a hill my transmission slipped. I let off the gas and it feathered a little until it shifted back into gear. It was fine after that with no Check Engine Light. But today as I was driving down the freeway, and I hit a bump that caused the transmission to slip again. When it shifts back then the Check Engine Light comes on. Then approximately 10 minutes later I was at a stop light. When I accelerated it didn’t go into first gear. I am stuck in whatever gear it’s in. At the next stop light I turned the van off then back on, and it shifted OK until I got home. What’s causing my truck’s problems and how can I fix it?

Hi there. You definitely appear to have a voltage issue with the vehicle. From what you are can be a bad connection at the battery, a failing alternator, or most commonly a bad ignition switch.

I usually start by checking the battery and the alternator first. If both of those are fine then I do a voltage drop test of the ignition switch. The ignition switch is the most common issue I have seen on this vehicle. If the switch is fine then it may have a bad connection someplace else, like the fuse box.

If are going to have this looked at, consider YourMechanic, as a certified mechanic can come to you home or office to diagnose the Check Engine Light and repair this.

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