Chevy Silverado and GMC Sierra Electrical and Computer Questions

z71bear

Hello,

I have a 2000 4WD Chevy Silverado with the 5.3 V8 with 49,000 miles. Today when I was headed home from work I noticed that Service Engine Light was on. I headed to the auto parts store to use their scan tool. I pulled out code P0440 “Evaporative Emission Control System Malfunction”

After a little research I found that it might have been caused by the fact the gas cap was not all the way tight. Is this true? Also will the MIL reset itself if the problem is gone?

What else could set a code P0440?

Thank you so much!

Jeb!

See Also
What Your Check Engine Light Is Telling You

repairdog

Have any auto store delete the code and it may also be caused by a hole in the line, bad sensor, purge valve, or vapor canister.

smurfluvr

I have an 03 silverado that I just dropped a new engine into. The original engine was a 4.8L and I bought a 4.8/5.3L to drop in it. The engine went in and connected up fine, but it is not starting by the key. If i bypass the ignition it will turn over. There is also a light that is on from the dash that has a symbol of a lock. Many people are stating that this might be a computer problem. Is there some kind of security lock, do I have to just reprogram the computer, or do I have to have a new computer put in? Also, if I need computer work, is the dealership/manufacturer the only place to get this kind of work done? Are there independent mechanics that do that kind of work?? Thanks for any help I can get.
And this is kinda an ASAP thing too .. thanks ...

huff94

I have a 1999 Chevrolet Silverado Z71. Sometimes it doesnt want to start. After you crank the ignition for a few seconds if finally starts. I have replaced the fuel pump/sending unit, and the filter. Still no luck. Also my fuel gauge is acting funny. When you close the drivers side door, and after the dome light goes off, the fuel gauge goes back up to where it was when the truck was running. I have seen the same posting, but havent seen any solutions. Please if anyone has any ideas let me know.

gangof4

gangof4

I have a 2006 Silverado LS 1500 WD ext cab, a 6 cylinder with 4 speed auto transmission.

Everything works fine except when I'm using cruise and doing about 55 and I reach a small hill, the tach jumps to twice the RPMs as the transmission shifts, then the RPMs abruptly drop to normal again. The tach is always in the safe zone.

The dealer said (without driving the truck) that this was normal, but it's kinda annoying. Is there a problem?

rcf8000

Can anyone tell me how many miles you have to drive after your codes have been cleared, and problems fixed, before you can run through emmissions. I just cleared and repaired air intake check valve(passengers side),and cleared code but emmissions station says I have to drive or wait or whatever, till whenever? I still have to retest, but when?

silver4803

The computer logs how many time and miles since clearing of fault codes. They want to see several cycles for the computer to report any problems. You will have to ask them. But I would think that 5 cycles and 100 miles should be okay for them.

fredk2

fredk2

I have a 2006 gmc duramax diesel 2500hd the change fuel filter comes on the display so I replaced it then did what the owners manual wrote to reset turn on ignition to run wait 5 sec. the push brake and gas peddle down at same time for 10 seconds it is reset but it dont seem to work is this reset by a timer or a senser?

canayjun64

Hi everyone,

Recently, my 2k Silverado 4.8L has been dificult to start when it's hot. I suspected my EGR valve so I disconnected it to see but got the service engine light on now. I know it's not the EGR now but the light stays on.

I remember my dealer telling me once how to reset this but I forgot. Could anyone help?

Thanks

jneal

From your description I would have to agree with the dealer.
Your RPMs do increase when the transmission downshifts but not as much as the tach would indicate. Any sensitive electronic meter will do that given a sudden change in input. It's called overshoot. I don't think you have anything to worry about.

jneal

First, go to AutoZone and they will read the code for free and then you will know what to look for. You should be able to turn the SES light off by disconnecting both battery cables and holding the ends together for a couple of minutes. That doesn't work on all vehicles so not completely sure about yours.

canayjun64

Thanks jneal. That's exactly what I did (sort of) I disconnected the negative cable from the battery for about 30 seconds. That did the trick.

Now I'll have to see why it's so hard to start when the engine is warmed up.

Thanks again!

lon986

My 2000 GMC 2500HD 8.1 L is reporting the following trouble codes:
1)MAF or VAF A ckt range/perf
2) MAF or VAF A ckt low input
3)IAT Sensor 1 circuit High Input
4) Manf Cntrl Veh. Spd
Idle Speed Control
Auxiliary Inputs

I have checked visually for any loose connections or vacuum hose issues.

Can anyone sugest how to isolate the problem to the root cause???

Thanks

jneal

#4 is probably caused by one or more of the first three.
I would check the MAF and the IAT sensor. Either one can cause all the others but I lean more toward the IAT sensor.

canayjun64

**UPDATE**

In regards to my previous posts, I have had my truck serviced and it turns out that the Fuel Regulator was causing a poor engine start up (when the engine is warm).

Just sharing the knowledge...cheers!

achieftim

I have 2005 1500 silverado and can't find fuse for chime when key in ignition - help!

talon03

I've been receiving the "battery not charging" message. I've replaced both the alternator and the battery with parts from Pep Boys. The terminal cables are clean. Additionally the voltage gauge in the dash fluctuates up and down at low RPM. Especially if you're running the lights and air conditioner. Any ideas?

talon03

myz71

I just changed my battery and was having similar problems. I took it into the shop today and they informed me that after replacing the battery, I have to start the truck, hold the brake, put the truck in drive and rev the engine to 2000 rpm for 2 minutes. This resets the computer and now mine works fine. I hope this helps.

jconnally

Problem: Start truck, radio won't play. No audio, display works in all functions. Ran to dealer, quick check, order new radio. Two days later, get in try to start truck, battery dead but radio plays. Towed to dealer replaced blower control with shorted resistor.

Same failure one year later on vacation out of state. Radio quit, go to local dealer tell him to check VIN in the system. Order same part. He thinks I'm nuts. Next day truck dead, but radio plays. Replaced blower control and on my way.

I can understand a shorted resistor causing a power drain on the battery, but why would it have an affect on the radio then restore it's operation.

I'm Stumped!

catam

Did you ever find the cause of your problem?

I have the same code on my 03 Suburban, and I know it is not the gas cap, I have replaced it, and cleared the code, but it came back.
Thanks for any info, Catam.

smithpb1

I don't have a solution but I am having a very, very similar problem. 1 1/2-2 months ago, audio system in my 03 Trailblazer would lose all audio but display and all functions would still work. It had been sporadic until recently. Took it to a dealer last week, quick check, and suggested to order a $500 radio. Then, 2 days later, battery went dead. Replaced battery and now no audio at all for 3 days now. How did the dealer diagnose the bad resistor?....because my next step is to call them back and request a more thorough recheck. Did you end up replacing your truck's radio? Thanks for any info you can provide.

jconnally

I was unable to find out how they came to the conclusion the problem was a resistor. But the GM part number is 89018597. Maybe if we gang up on Chevrolet, maybe they'll take care of some of our costs. I also have an 04 Trailblazer, so I'll brace myself for the same with it. I don't know if it's because it has the BOSE sound system, but I've heard that there are some strange things that are linked to it.

In a few more days, I plan to do battle with the Chrevolet dealership after I get a little more ammunition. I found one case almost identical to mine on another forum site, so if I do find out anything it will be posted!

gholde

I have a 2000 silverado ext 4x4 5.3l that I have been having a little
problem with.

A few days ago I was driving and noticed the battery light come on and
the volts gauge was reading around 10 -11volts. I turned off all
accessories and headed her for home.

Once home I took the battery (delco factory) to Canadian tire for them
to test it. It tested ""replace". So I did with a new 875cca terminator
battery. When I installed the new battery the truck started fine but I
noticed the battery warning light was still on. I let it run for 20min
or so to see if it would charge. (or what ever was wrong might
magically fix itself) The light didnt go out so I tried some of the
accessories to put a load on it. The wipers and blower motor ran but
noticeably slowly.

I just decided to let the truck run with all accessories off. The
battery light didn't go out so after running for 1/2 hour or so I shut
off the truck and the the battery now shows 11.7V across the terminals.

I charged the battery back up to show 12.6V across the terminals.

Then I started the truck and checked the voltage across the terminals
with the truck running (no access on at all)......11.3V....What
the.....and the bleeping battery warning light is still on.

I tried revving the truck to 2000-2200 rpm (no access on at all) and
the voltage across the battery went up to 11.49 at one point but it
also fluctuated down to 11.27 also....

Does this sound like a new alternater to go along with my new
battery???? What are the odd that both the battery and alternator would
crap on the same day???

PS. I have never had another issue with this truck until this

bmxkid7117

My brother and law had this problem sorta with his maxima. you more than likely put too much strain on your alternator with the poor battery, which could result in this behavior. i was always told (although this doesn't have anything to do directly with your problem) never to just jump a dead battery and then drive it. let it sit for a while to accurately charge the battery without putting strain on the alternator that isn't necessary.

good luck

tonkatoy1

I would be suprised if your battery had a problem at all. If the person that tested the battery didn't charge it first, then of course it will look like it's bad when in all reality it's just dead. Batteries have to have a good charge on them before you test them. Your alternator is not working. Even if you have a bad batery, your alternator will still keep your truck at about 14.5 volts.

fsurob4

I just bought a 97 z-71 suspension lift kit dynomax exhaust, and 36 inch irok radials. Dude took real good care of the truck, it has 139000 miles, but they are from driving 20 miles to work then 20 miles back home every day. The other night me and my buddies decided to go out the spot and hang with some friends(17 years old, still in high school, NC), well i put it in 4wd
and might have gone a little to hard because it was night and i under estimated the whole but it wasnt bad at all. Well i hit the whole and bounce twice and everything just goes out lights radio every thing i was wondering if anyone new what this was, about 1 min later it turned right back on and cranked like a chevy does quick and easy and drives fine. I would appriciate some feed back, thanks.

fsurob4

this was the first time taking this truck off-road, so it has never done this before it just randomly did this.

gbrewer

I have a 2003 2500HD 6,6 Duramax. My passenger door electronics quit working over night. Nothing works except the blinker in the mirror. The truck has no response to the remote entry. The 2 back doors do respond to the controls on the drivers door. My brother has a 1500HD with the same problem, has anyone else had this problem?

fsurob4

KCRam

Sounds like a battery cable isn't tight. You may want to invest in a new set, considering how much the truck has been driven..

fathergoose

I have a code code 1637 L generator circuit.

I replaced the alternator, Code came back.

Jumped a wire directly from the ecu to the generator, for the voltage signal, cause I tought It could be short somewhere. The code still came back. Does anyone have experience with that perticular code?

fivepoint3

I have an 03 reg cab silverado 2wd and the same thing is happening to my truck. My passenger door is dead, nothing works on it except the blinker in the mirror and the keyless entry dosen't work either on both doors. I don't know about you but my driver side mirror doesn't fold in, I can adjust the mirror but it won't fold in. This all happened after I picked my truck up from the body shop (minor scuff, not major damage). The body shop printed out the bulletin for me to take to the dealer so they can fix the problem. The bulletin said something about the truck losing its program and all the symptoms it listed was what me and you have (doors/windows/mirrors not working) I lost the bulletin so I will have the body shop print it out for me again and give you the info so you go to the dealer and have them check it out. Sorry if this is not much help but I figured it was better than nothing. Email me back if find something out cuz I realy want to get this fixed

gbrewer

Sounds like we have the same problem, My brother found the control module for $50.00 at a salvage yard in Lexington for his, when he gets it I will let you know if that fixes it. The module at the dealer cost around $300.00. If you can send me the bulletin.

Thanks for the reply.
Gene

gasa765

gasa765

My brother in law as a '99 Silverado, manual transmission. The problem seems to be if when you open either door, and accidentally hit the door lock button, the truck won't start until he waits for 15 minutes or so. He's taken it back to the dealer he bought it from and had them go through it and they can't figure out how to resolve the problem but they indicate it has something to do with the factory installed alarm system. He's spoken to several alarm installer dealers and from what I understand it's not as simple as just disconnecting the alarm.

Has anyone else had this problem and what did you do to fix it?
Thanks

fivepoint3

Man I went to the autobody guy and he said he spent hours trying to find that bulletin but could not find it so he sent me to the chevy service department and they don't know of any bulletin like that for my truck, now I'm [non-permissible content removed] out of luck, I already spent $134.00 on a new door control module that I don't think I can return. But anyway good luck with your control module (I'm assuming it's a body control module). And let me know how it works out. I'll keep trying to get a hold of that bulletin

gbrewer

That how it goes can't never get anything when you actually want it. I took all my fuses out waited a little while put them back in and mine is working like new, so my guess is what ever it was reset when I pulled the fuses. I would like to get a copy of that bulletin if you can get a hold of it. Thanks for the help

fivepoint3

glad to hear you fixed your problem, I've looked everywhere for that bulletin and could not find it, I don't know if I threw it out or what. I guess my next step is to do what you did and see if that helps.

cbaker3

Hey guys, I have a '97 Z71 SLT. It has the electronic mirror with the compass and temperature readings. The problem is that the temperature readings are not working. On the bottom of the mirror, when you press the temp button, the LED comes on, but nothing else happens. Any idea what could be causing this?

Chris

mhead60

mhead60

i have a 2003 sierra 1500hd and my battery not charging light comes on but i can drive all day and my battery never goes dead does anyone know what could be making this light come on i have change my alternator and my battery and it still does it

gholde

kwh924

I ahve a 2000 Silverado Ext cab Z71 with the 5.3 like yours and I've had similar problems. On mine it turned out the cables were so corroded that it kept interupting hte batteries connection causeing the truck to actaully cut off and on while I was driving it with the battery light on. The side post batteries they used are real bad about corrosion so that might be the problem but I wouldn't be surprised if it did toast your alternator too because mine was fine after I replaced the cables for a little bit and nowthe alternator seems to be burning out.

pddave40

pddave40

security system randomly turning on/off. what could be causing this? have removed battery from key fob. taken to dealer, who is at a loss. anyone had this problem?

jay66

i have an 03 1500 hd and have the same problem. what fuses did you pull and did your problem come back. what ever information you have is greatly appreciated.

geo9

Disconnect one battery canle for a few minutes.
Easier than guessing on which fuse !

jay66

I disconnected the battery cables and pulled every fuse that had anything to do with power windows, doors, and locks. Still nothing. I will probably just take it in when I get a chance. Thanks for the reply.