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Wolf0r
Top Member
USA
2181 Posts |
 Posted - 03/24/2009 : 07:32:30 AM
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| I have a 99 GMCV with the CAT 3126. I get a check engine and intake heater lamp at the same time under a load. The engine feels like it's derating but I have limited data access with my scan tool. Fuel rate stays normal but boost will drop to 16psi at 99% throttle. Then eventually when I level out, it's back to normal. My question is will the intake heater circuit being open cause drivability problems on a warm engine? I have checked the wiring of the intake heater and it's fine, I haven't checked the PCM wiring yet. I think there is just one that grounds the solenoid left to check. |
Edited by - Wolf0r on 03/31/2009 09:29:01 AM
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 03/27/2009 : 2:33:05 PM
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| Ok, I have checked the circuit from the PCM to the grid solenoid. I can ground the wire and the grid works. I sent this bus to CAT since my Nexiq doesn't let me into bi-directional control. I wanted to actuate the grid through the PCM to see if I had a driver problem. Caterpillar has 10 hours invested in this rig plus did a valve adjustment and still hasn't came up with anything. They were able to duplicate the concern but not isolate a problem. Now they say take it to a transmission shop. WTF!?! |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
Edited by - Wolf0r on 03/27/2009 2:38:48 PM |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 03/30/2009 : 11:54:09 AM
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| Well it's back to me again. I hooked a test lamp to the unplugged heater harness. The heater is being commanded on, I get a light. Coolant temp and air intake temps are reading correctly. Engine is at 180F. Why does it turn on the intake heater during acceleration? Hmmm |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
Edited by - Wolf0r on 03/30/2009 11:55:16 AM |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/30/2009 : 12:59:19 PM
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| I have to call over to my Cat dealer for something else I will ask them while I'm on the phone. These guys are generally very good. |
Bryan |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/30/2009 : 2:57:38 PM
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Might be be the coolant temp. sensor. Another thing to look for is a wire with the insulation rubbed off between the fire wall and the engine. You might also check to see if the engine is staying put. (loose motor mount). These are all ideas from the Cat dealer that I know. He said that if the signal from the coolant temp sensor says that the temp is below 130 degrees then the intake heater light might want to come on. The rubbed wire might be giving a false signal to the computer and telling the intake heater to come on. This all makes sense if the engine is torquing over aginst a wire somehow.
Let us know what happens. |
Bryan |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 03/31/2009 : 06:18:17 AM
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| Thanks for the tip. I am going to pull the inside sheetmetal so I can see the back of the engine. Everything under the sun is bolted through it, lol. |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 03/31/2009 : 09:27:10 AM
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+Rep to you bwest!, you were right about wire rubbed through. I didn't want to get involved pulling that trans/engine sheetmetal inside. But I did, this guy had a VCR,shelf, trashcan, and crap screwed to the plate. It looked like the stuff you find behind your clothes dryer when you pull it out. NASTY! The purple/white VSS wire had rubbed through the insulation and was touching the bellhousing. Thanks for your advise, sometimes it takes another person to find that missing piece of the puzzle. Here is some bus porn for ya.
Here's where we go after work for a beer or 3.
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“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/31/2009 : 12:20:23 PM
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| Glad I could help but my cat dealer deserves the credit. I'll pass along the thanks. |
Bryan |
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Thomasbus24
Administrator
USA
4547 Posts |
Posted - 03/31/2009 : 2:45:29 PM
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quote:
Originally posted by Wolf0r
[br Here is some bus porn for ya.
MMM yeah...take off that doghouse! |
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B. Busguy33
Top Member
USA
3444 Posts |
Posted - 03/31/2009 : 2:58:53 PM
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quote:
MMM yeah...take off that doghouse!
LOL!! |
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Mechan1c
Top Member
USA
853 Posts |
Posted - 04/01/2009 : 10:31:16 AM
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| Man I feel for you FE mechanics! |
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Thomasbus24
Administrator
USA
4547 Posts |
Posted - 04/01/2009 : 1:05:37 PM
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| RCA jacks and a serial cable. WTF did the bus driver have in there, a plasma TV hooked up to laptop? |
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Mechan1c
Top Member
USA
853 Posts |
Posted - 04/01/2009 : 1:25:55 PM
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| Camera?? |
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bwest
Administrator
United States
3820 Posts |
Posted - 04/01/2009 : 1:57:13 PM
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Hey Thomasbus24, You need to get out into the real world every once in a wile. Every district I know of around us has cameras on busses. If I had to guess I would say they are using a Gatekeeper brand VHS system.
Just ribbing (that real world thing), you know that right? |
Bryan |
Edited by - bwest on 04/01/2009 1:59:31 PM |
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Thomasbus24
Administrator
USA
4547 Posts |
Posted - 04/01/2009 : 2:24:39 PM
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I've just never seen an antique serial cable used with a video system!! What kind of cheap, made-in-Honduras system is gatekeeper? We ran REI bus watch VHS systems (yeah start laughing now)--so no cables like that.
I admit I was starting to re-think the "Bus Porn" comment. lol |
Edited by - Thomasbus24 on 04/01/2009 2:27:18 PM |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 04/01/2009 : 2:45:58 PM
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| It's a farmer/bus driver's bus. I think he washes it once a year. He actually has two video cameras in there. The one you see the plugs for is a silent witness. He also had a safetyvision dvr mounted behind the inside mirror. You should see the busses I service that we lease to the coal mines. |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 04/01/2009 : 2:50:24 PM
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quote:
Originally posted by Thomasbus24
I've just never seen an antique serial cable used with a video system!! What kind of cheap, made-in-Honduras system is gatekeeper? We ran REI bus watch VHS systems (yeah start laughing now)--so no cables like that.
I admit I was starting to re-think the "Bus Porn" comment. lol
By bus porn I meant bus pictures. LOL I am a member of a ford forum and we call the imbedded pictures ford porn. |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Thomasbus24
Administrator
USA
4547 Posts |
Posted - 04/01/2009 : 3:07:06 PM
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| Well I would hope that is what you meant!!! As for the farmer driver annual washer guy...he have a brother in Ohio? Had one who was the same way...end of the year he just took a power washer and sprayed down the entire interior this one time. Yes, all of the damage you are imagining was very real. |
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bwest
Administrator
United States
3820 Posts |
Posted - 04/01/2009 : 7:57:55 PM
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| Farmer/ Bus driver? You guys are funny! When I was in school my driver never washed his bus. He would have a chew in his mouth and you better be fast getting off or on because he was going to spit right behind you out the door. You can imagine what the step well looked like. Well about six years after I graduated I went to work for the same school. He was still driving. Real nice guy (when your not a student). But he still didn't wash his bus. It got washed once a year (weather it needed it or not) by me. Oh yea, he quit the spitting thing a couple of years after I graduated. Seems someone complained. He didn't quit chewing, just spitting. Yea that's gross! |
Bryan |
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clawson
New Member
2 Posts |
Posted - 12/02/2010 : 5:40:47 PM
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I have a question about the 3126 intake heater.. we have changed the relay and still the intake heater doesn't work? What else could I check.
claw |
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bwest
Administrator
United States
3820 Posts |
Posted - 12/03/2010 : 05:18:09 AM
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| Been a long time since I have had trouble with one of mine I don't remember eveything. But be sure you have power on the large wire coming to the solinoid. Then turn on the key (when it's cold) and make sure you have power coming in on you signal wire. If all that's there make sure your getting power at the heater post. |
Bryan |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 01/07/2011 : 12:56:11 PM
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| Anyone have a part number for the coolant temp sender (for the gauge not the ECU)? I have two 2002 GMCV that the gauge is inop. The ecu sender is reading normal on the scanner. |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 01/13/2011 : 08:08:53 AM
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| 141-2729 is this a good number? That's what is on the sender, CAT gave me the wrong part again even after giving the ESN. WTF? |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Topic |
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CAT 3126 DTC 70 Intake Heater (FIXED)
