I have a 2002 Trailblazer vortec v-6 and 151k. taking a little drive in the neighborhood on saturday SES and REP lights came on, limped home (only 2 blocks away) and hooked up the code reader. P1515, googled it, and found an article about throttle body cleaning. I had cleaned it a couple of years ago, so I knew it was probably dirty and it is a simple process anyway. I put everything back together, and ran my errands with no lights what-so-ever.
Easter Sunday...driving to easter dinner 90 miles away, cruising at 75mph when a semi that was weaving back and forth in his lane but me over the edge and I felt the need to just get around him as fast as I can. stepped on the gas, vehicle started to accelerate, rpms went up for extra power, then...SES and REP lights. slowed down, pulled over turned off vehicle for a minute or 2 and restarted. SES light, but everything else was fine. Continued the drive, read code, P1515. Cleared the code and drove back home 5 hours later. Accelerated fine, no lights everything a-ok.
MY QUESTION...Where do i start to diagnose? I know that I should probably check for wire fray as this seems like a culprit. Already cleaned the throttle body, however I did notice when I had it out that there was a rattling noise coming from the sensor housing like there was something broken off and rattling around inside. When I opened and closed the butterfly valve it kind of made a little bit of a grinding noise like un-greased ball bearings. Also when cleaning the butterfly valve, it got stuck in the open position when spraying with the B-12 Chemtool cleaner. I kind of wiggled the valve a little bit and it finally released and shut. Could it be that the throttle body needs to be replaced? I have never worked on one, other that the previous cleaning a few years back, so I'm not sure what would be considered a "normal" sound would be when opening and closing the valve.
I'm kind of ruling out the wiring as my fan clutch was replaced several years ago but I am not ruling it out.
Feedback is much appreciated!
Easter Sunday...driving to easter dinner 90 miles away, cruising at 75mph when a semi that was weaving back and forth in his lane but me over the edge and I felt the need to just get around him as fast as I can. stepped on the gas, vehicle started to accelerate, rpms went up for extra power, then...SES and REP lights. slowed down, pulled over turned off vehicle for a minute or 2 and restarted. SES light, but everything else was fine. Continued the drive, read code, P1515. Cleared the code and drove back home 5 hours later. Accelerated fine, no lights everything a-ok.
MY QUESTION...Where do i start to diagnose? I know that I should probably check for wire fray as this seems like a culprit. Already cleaned the throttle body, however I did notice when I had it out that there was a rattling noise coming from the sensor housing like there was something broken off and rattling around inside. When I opened and closed the butterfly valve it kind of made a little bit of a grinding noise like un-greased ball bearings. Also when cleaning the butterfly valve, it got stuck in the open position when spraying with the B-12 Chemtool cleaner. I kind of wiggled the valve a little bit and it finally released and shut. Could it be that the throttle body needs to be replaced? I have never worked on one, other that the previous cleaning a few years back, so I'm not sure what would be considered a "normal" sound would be when opening and closing the valve.
I'm kind of ruling out the wiring as my fan clutch was replaced several years ago but I am not ruling it out.
Feedback is much appreciated!
