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sprinkles08
sprinkles08, ASE Certified Technician
Category: Mercury
Satisfied Customers: 22301
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
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My 03 sable maintains whatever speed I am driving when I

Customer Question

My 03 sable maintains whatever speed I am driving when I take my foot off gas pedal. Allready replaced tps and idle control sensor
Submitted: 1 year ago.
Category: Mercury
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

The throttle position sensor signal voltage staying high is a common cause of something like this. The idle air control motor staying open too far could also cause it. If the TPS and IAC themselves have been ruled out it's still possible that there is a wiring issue with either, and it's also possible that the IAC driver circuit in the powertrain control module has failed.

A vacuum leak will also cause idle to be high.

The first step in diagnosing the problem is to check for fault codes. Have you checked for codes?

Customer: replied 1 year ago.
no.
Expert:  sprinkles08 replied 1 year ago.

Do you have a scan tool or code reader?

Customer: replied 1 year ago.
no
Expert:  sprinkles08 replied 1 year ago.

A scan tool will most likely be needed for an accurate diagnosis.

Is the engine light on?

Do you have a big chain parts store such as Autozone near?

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