Car would not go over 30 mph

DAVY CARR

MEMBER
2005 CHRYSLER 300
90,000 MILES

When I crank up and start driving my vehicle doesn't go over 30 to 35 miles per hour. Sometime I can put it in neutral and then put it back and drive and then I can get up to speeds of 50, 60, 70 miles per hour but within the next two minutes It'll jump back down to only 30 miles per hour and I can't go over 30 miles per hour. Also, the lightning bolt symbol appears on the dashboard. Can you please help me and tell me what my problem may be?

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This sounds to me like your throttle body is dirty and interfering with the Throttle Position Sensor (TPS) signal to the Power-train Control Module (PCM). Without this signal the PCM has no idea how much air is entering the engine. Since there is a real possibility that the engine could go lean and blow up, the PCM goes into "limp mode" where the engine is governed and will not go faster than, in your vehicle's case, it sounds like 30 mph. I have included a few links for you down below to go to.

https://www.2carpros.com/articles/symptoms-of-low-engine-power
https://www.2carpros.com/articles/engine-has-low-power-output
https://www.2carpros.com/articles/throttle-actuator-service

I have included the reset procedure for the transmission that must be performed after the throttle Bore cleaning to return to normal operation. Please get back to us with what you find out.

Thanks,
Alex
2CarPros

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