And go to the link so you have the factory service manual troubleshooting flow charts, so you can understand what sets the codes, and how the components operate.
CK5
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89 high idle problems, surging, help!
- Thread starter toppryority
- Start date
toppryority
Registered Member
got it.... i do not have one of these voltage meters other than an OHM would you recommend one? I have a lowes and autozone close by
Any DVM should have volts, you needs volts. OHMs are also a good tool.
If you are cheap, and you have one close by, you can get a multimeter from harbor freight for less than $20. It will do most everything you need. I don't care what anyone else says, if you don't have a multimeter, you aren't working on your vehicles properly. You can't repair a vehicle if you can't diagnose problems. Well, you can, but replacing parts is a heck of a lot more costly than buying a cheap meter.
A good (read: accurate) meter will cost you substantially more, but if you like nice tools, go for it. I would hate myself if I dropped a good meter though.
A good (read: accurate) meter will cost you substantially more, but if you like nice tools, go for it. I would hate myself if I dropped a good meter though.
toppryority
Registered Member
alrighty then, got me an actron cp7677 auto troubleshooter multimeter, loaded for bear now.. soon as i figure out how to use it, i will get those test done lol. I assume I am performing those tests with the ignition switch on?
Dam, you start with good stuff!
toppryority
Registered Member
voltage began at .80 and ran to 4.45 at full throttle. supposed to begin at .5 right? what does that tell me, wherein lies the problem there? any ideas?
Yes technically it should be .54 volts, but realistically if it is under 1.12 volts it is fine... I know people will argue this but that is the way the code is...
Why is it so high? Is your throttle sticking? Have you turned the little idle screw in? If you pull throttle closed will it go down? If you have worn blades or sticky throttle and it closes more after you start the truck it will set a TPS code. This is because the ECM reads the TPS voltage when it starts and sets a "0 Percent" if it changes to -1 percent then a code sets...
Biggest point of a TPS code is a glitch in voltage! Read it again and open SLOWWWWWLY and watch for smooth rise, if you see a glitch it's bad.
Why is it so high? Is your throttle sticking? Have you turned the little idle screw in? If you pull throttle closed will it go down? If you have worn blades or sticky throttle and it closes more after you start the truck it will set a TPS code. This is because the ECM reads the TPS voltage when it starts and sets a "0 Percent" if it changes to -1 percent then a code sets...
Biggest point of a TPS code is a glitch in voltage! Read it again and open SLOWWWWWLY and watch for smooth rise, if you see a glitch it's bad.
toppryority
Registered Member
no throttle sticking, idle screw not been touched to my knowledge, blades look fine, the TPS unit itself is new just replaced by a local gm dealer within the last 2 weeks, is there a solenoid somewhere I am missing?
Well tell them to fix the dam thing?
Check the prongs in the plug and make sure they are not collapsed flat. Need to be tight on connections to TPS sensor. Check wires at plug, follow wires back in harness and look for broken, corroded etc... check your 2 ground connections on engine, one by thermastat housing and one back on manifold near coil... need good grounds! Are the wires broke, corroded, rusted?
You could loosen the screws on it and twist it a little or bend the tang on back to get voltage down if you want.
black dawg
1/2 ton status
was the issue identical before they replaced the tps?
I would check that thing over and over fast and slow, and try to get it to screw up.
I would think about testing tps signal at the ecm.
Just for something to check, I have seen the wires get bare where the harness runs against the intake.
I would check that thing over and over fast and slow, and try to get it to screw up.
I would think about testing tps signal at the ecm.
Just for something to check, I have seen the wires get bare where the harness runs against the intake.
take a HARD look at the ground connection on top of the intake back by the coil... take it apart, check the ring connectors good, clean and reinstall...
toppryority
Registered Member
yes, the situation was identical before they replaced the tps,. I will trace all wires back to the coil and see if anything is kinked or poor ground. thanks guys for all the help. once i do those, will respond with I hope successful outcome. keep you posted..... thanks again
how do you test the signal at the ecm? and where is the ecm located, what does it look like? Is it under the steering column?
how do you test the signal at the ecm? and where is the ecm located, what does it look like? Is it under the steering column?
ECM is behind glovebox, take it out and you'll see it.
Wiring diagrams are here:
http://coloradok5.com/forums/showthread.php?t=302678
Pin C13 Dark Blue wire at ECM, check voltage there with key on, just like you did at TPS, may need someone to open throttle...
Wiring diagrams are here:
http://coloradok5.com/forums/showthread.php?t=302678
Pin C13 Dark Blue wire at ECM, check voltage there with key on, just like you did at TPS, may need someone to open throttle...
toppryority
Registered Member
Unreal, I just took the twin flowmaster mufflers off and replaced them with turbo mufflers just because the flowmasters were so loud and created so many fumes. NO MORE CHECK ENGINE LIGHT, idles perfectly and runs smoothly. No more codes coming up. You guys got an explanation on this or is this a fluke and I should expect this to start over again?
I'm going to defer to Mark on this one, but I don't see where exhaust should cause a problem, especially with idle, unless there was a leak before it.
Headers or anything like that, especially mufflers, won't change flow at idle enough to put the ECM outside of what it can adjust for (which is when a code would be triggered for lean O2), at least to my knowledge.
Headers or anything like that, especially mufflers, won't change flow at idle enough to put the ECM outside of what it can adjust for (which is when a code would be triggered for lean O2), at least to my knowledge.
Why me?
It makes no sense to me either? Unless they were plugged, and the inside of a flowmaster is hard to plug. Unless they rattle from broken baffle causing a restriction.
Or did you do something else with exhaust? Like fix a leak before or around O2 sensor?
Did you drive and do WOT to see if it happens still?
It makes no sense to me either? Unless they were plugged, and the inside of a flowmaster is hard to plug. Unless they rattle from broken baffle causing a restriction.
Or did you do something else with exhaust? Like fix a leak before or around O2 sensor?
Did you drive and do WOT to see if it happens still?
'Cause you know more than I do on how that code would be triggered! On any reasonable motor, I can't see the ECM running out of adjustment due to increased airflow, at least at idle, no matter what mods you make.
black dawg
1/2 ton status
just a fluke, unless the grounds were disturbed somehow. Any welding?
Have you taken a look at the grounds on the motor? I have seen some that the wire itself was broken down a half inch from the eye.
Have you taken a look at the grounds on the motor? I have seen some that the wire itself was broken down a half inch from the eye.
