# Reduced engine power?

**URL:** <https://community.cartalk.com/t/reduced-engine-power/68934>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, uplander\
**Created:** [October 25, 2011, 1:32pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934 "2011-10-25T13:32:41Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![sickofcars](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@sickofcars](https://community.cartalk.com/u/sickofcars)\
**Post date:** [October 25, 2011, 1:32pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/1 "2011-10-25T13:32:41Z")

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I have a 2007 chevrolet uplander. Yesterday it started giving a message of reduced engine power and the engine light comes on.

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [October 25, 2011, 1:39pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/2 "2011-10-25T13:39:47Z")

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Nobody can diagnose this via cyberspace.  
The presence of an illuminated Check Engine Light means that a trouble code has been stored. So–you need to take the vehicle to an auto parts retailer that will check the OBD system for stored trouble codes.

After getting the code(s)–in a format similar to P0123–come back to this thread and post the exact codes for specific advice.

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**Author:** ![sickofcars](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@sickofcars](https://community.cartalk.com/u/sickofcars)\
**Post date:** [October 25, 2011, 1:43pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/3 "2011-10-25T13:43:07Z")

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Ok. I will do that.

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**Author:** ![sickofcars](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@sickofcars](https://community.cartalk.com/u/sickofcars)\
**Post date:** [October 25, 2011, 7:59pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/4 "2011-10-25T19:59:27Z")

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I got a code P1516. What is that??

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**Author:** ![mark9207](https://avatars.discourse-cdn.com/v4/letter/m/71c47a/32.png) [@mark9207](https://community.cartalk.com/u/mark9207)\
**Post date:** [October 25, 2011, 8:19pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/5 "2011-10-25T20:19:15Z")

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A quick Web search on this code turns up that this code indicates is a problem with the throttle actuator control system circuit. Other forum members on other forums recommend checking for damaged wires or dirty/loose connections on the throttle actuator control system and cleaning the throttle body. I have no actual experience with this system (drive by wire throttle was still very new when I got out of auto repair) but this seems like a good place to start with diagnosing this issue.

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**Author:** ![sickofcars](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@sickofcars](https://community.cartalk.com/u/sickofcars)\
**Post date:** [October 25, 2011, 8:23pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/6 "2011-10-25T20:23:31Z")

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thank you!!

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [October 25, 2011, 8:29pm UTC](https://community.cartalk.com/t/reduced-engine-power/68934/7 "2011-10-25T20:29:18Z")

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As Mark says, this code indicates a problem with the TAC module.  
However, rather than having a mechanic simply change this part, you should remember that a wiring problem could be to blame, rather than the module itself. Checking for chafed or pinched wiring could potentially save you the cost of replacing the module.