04 Silverado reduced engine power message

[Carbon12]

Vehicle: 2004 Chevy Silverado 1500 Z71, 5.3L, 85000 miles

Problem: goes into reduced engine power mode when AC on

The problem began last summer and has continued this summer. Only occurs when AC is on. Has never occurred when AC off. The problem usually occurs when having to slow down for traffic or red lights and then putting foot back on pedal seems to trigger it. Haven't really seen it occur during heavier acceleration. Took it to dealer last summer but the engine trouble code (don't remember exact code) was not specific enough to pinpoint the problem so they checked the wiring which is a known issue and found no problem. Googling this seems to indicate the problem is bad/loose wiring, defective throttle body, or defective gas pedal position sensor. However, if it was one of these I think the problem would occur all the time, not just when ac is on. It's almost like the truck thinks it's over heated but no abnormal temp is shown on guage. It usually runs the typical ~ 210 F. Has anyone else experienced this and how did you fix it?

Thanks.

 

[turtlevette]

Did you connect a scanner to look at the temp?

 

[Chris142]

X2.is there coolant in it?

 

[userfriendly]

There is a wiring harness to your clutch fan, check that for damage and replace the clutch assembly which is 11 years old.

The above items on new vehicles are not covered by the power train warranty, but expires with the basic warranty.

Will store bought scanners pick up those codes?

 

[ragtoplvr]

1. The gauge on the dash is not connected to a temperature sensor. It is connected to the computer. They stablize it. This way the customer does not see the temp rise and fall as the fan cycle on and off.

2...Do you have an electric fan, and does it work. If clutch fan, does it work

3. You are probably overheating. When was the last time the AF was serviced.

4. it is NOT AC clutch.

5. A scan tool can read true temperature.

Rod