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1997 buick century P0502 code


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gilaine
User

Sep 26, 2011, 4:13 PM

Post #1 of 2 (4147 views)
1997 buick century P0502 code Sign In

We have a P0502 code (speed idle sensor low input). Hard to fix?? Would this contribute to loosing our odometer reading? Also transmission not shifting properly? Any help appreciated. Thanks


Discretesignals
Ultimate Carjunky / Moderator
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Sep 26, 2011, 6:52 PM

Post #2 of 2 (4111 views)
Re: 1997 buick century P0502 code Sign In

Don't know if it is hard to fix until the problem is troubleshot. Could be a wiring problem, faulty speed sensor, problem with the tone ring in the transaxle, or even the engine computer. Your guess is good as mine until the system is troubleshot to isolate the cause and effect.

The vehicle speed sensor on the transmission sends out an AC voltage signal to the engine computer (PCM). The engine computer convert this AC signal to vehicle speed. The engine computer uses that information to time the shifting of the transmission. If the signal is lost, the computer doesn't known when to shift the transmission and defaults the transmission to 3rd gear. You will also lose your speedometer/odo if the signal doesn't reach the engine computer because the engine computer gives the vehicle speed information to the instrument cluster and the cruise control module.

You or a mechanic needs to troubleshoot the circuit for the vehicle speed sensor and determine why the signal is missing.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 26, 2011, 6:56 PM)






 
 
 






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