cat accert
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rufus

New York, NY

#1 Jul 21, 2012
Can someone explain how the variable valve accuators work and wh they do? Also what is the purpose of the precooler? Is the intake air that hot because it is compressed so much. Basically I want to understand what is different between and accert and a pre-emission road tractor motor c15. Also what does the coolant diverter valve do?

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#2 Jul 22, 2012
rufus wrote:
Can someone explain how the variable valve accuators work and wh they do? Also what is the purpose of the precooler? Is the intake air that hot because it is compressed so much. Basically I want to understand what is different between and accert and a pre-emission road tractor motor c15. Also what does the coolant diverter valve do?
The IVA system (Intake Valve Actuator) is composed of an oil pressure sending unit, an oil-flow control solenoid, and six VVA's (Variable Valve Actuators), one for each cylinder. The VVA's hold the intake valves of the engine "open" a little longer than the camshaft/rocker arm assembly does. This enables the engine to "take-in" more air, producing a higher "boost" pressure, and also helping to completely "burn" the fuel injected into the cylinder. The oil pressure sending unit tells the ECM when to open or close the oil-flow control valve, so that a minimum of 42 psi is maintained throughout the IVA system. This oil flow also enables the jake brakes to work, as well.

The Pre-Cooler doesn't "cool" the air, it actually "heats" it up! It is designed to "cool" the antifreeze inside the engine, and heats up the intake air in the process. The "coolant-diverter valve" opens & closes to "regulate" the flow of coolant thru the Pre-Cooler. When the engine is cold, the valve opens and the engine coolant "heats" the air to warm the engine up. During normal operation on the road, the diverter valve opens whenever the engine temp starts to climb, and uses the intake air to "cool" the radiator. This system can reduce the overall engine temp by 10 degrees or more!

Hope this answers your questions :)
rufus

New York, NY

#3 Jul 22, 2012
Ken thanks for the explaination. Is it counter productive to "heat" the intake air? I thought that the cooler that is the more it can atomize in the cylinder? And as far as holding the intakes open longer is that the reason for the twin turbos to help create more boost, so that more air can be packed in the cylinders? With all of this why aren't these motors twice as strong as a pre-emission and why are they not as fuel efficient? Have they changed the timing, or changed the injection timing/ fueling rates. I read a lot about low nox. How do they accomplish this?

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#4 Jul 23, 2012
Normally it would be counter-productive to "heat" the intake air, especially on a lower-volume single turbo system. The reason they went to twin turbos in the first place was to meet 2004 EPA emission requirements. Their idea was to move more air thru the engine to produce a "cleaner burn", but they also "cut" the amount of fuel to the engine, as well. This is why the early versions (03 & 04) had power & fuel mpg issues. The ECM was reconfigured for the 05 & 06 model years, resolving the fuel & power issues. You can "flash" the older ECM's with a new "master file" & improve the performace drastically, if you know what you're doing.

The "basic" timing has not changed & the engine blocks are identical. The Acert head is different from the single turbo, and has the Pre-Cooler & twin turbo set-up. The ECM fine-tunes the timing by controlling when the injectors open & for how long, also by using the VVA's to control the intake valves. The ECM uses info from ALL the engine sensors to determine the actual timing.

To meet the 2007 EPA emission requirements, Cat went to the DPF system (Diesel Particulate Filter). It was the biggest mistake they ever made, in my opinion. The system was poorly designed & had an extremely high failure rate. I would not recommend buying a 2007 or newer C-15!
rufus

Albany, NY

#5 Jul 23, 2012
Great thanks for your answers. That helps me understand a lot. We just cleaned out the radiator charge air and condensor and that helped about .5 mpg. I think the fan isn't on as much and the intake air is cooler. How do they try to lower the nox? Is that thru different fueling times and patterns? I see guys complaining that new flashes with low nox also hurt fuel economy. Also what is the power band with the twin turbo? I cut the low and intermediate gears to 1500 in 18spd so that they would progressive shift. They complain though that the turbos don't spool up until after 1500rpm. What are your thoughts on this.
Thanks

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#6 Jul 23, 2012
It's controlled by the timing. The power band on these is 1100 to 1500, peak torque develops at 1200. When I drive, I shift at 1500.

When we got the 2007 KW's (with 2006 engines) they were set at 1600 rpm in lower & intermediate gears, 1800 in the top 4. The engines were rated at 475 hp matched with 13 speeds. I turned up the lower & intermediate gears to 1800, turned the top 4 to 2100 so they never run out of pulling power on the hills. I re-rated the engines to 550 hp, set the speed governor at 75, changed FLS & FTS settings. The end result is a truck that will pull most grades in the top 2 gears, rarely dropping below 60 mph. Overall fleet fuel economy is 5.8 to 6.5 mpg, depends upon the driver!

We recently finished cleaning all the radiator/charge air cooler/condenser setups also, seeing engine temps drop 10 degrees on average.
rufus

Albany, NY

#7 Jul 24, 2012
Ken thanks for the answers. Your guys must be good at progressive shifting. What are the FLS and FTS settings?

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#8 Jul 25, 2012
rufus wrote:
Ken thanks for the answers. Your guys must be good at progressive shifting. What are the FLS and FTS settings?
Would you believe that fuel mileage is coming from W-900's, the least aerodynamic truck that Kenworth builds? Plus, we're "meat-haulers" with running reefers...always loaded heavy!

We give them enough power & torque to "skip-shift", and explain to them how to accomplish this. 2, 3, 4, 5, 6, 8, 10, 12 then 13 OD. Run the engine up to 1500, shift, comes back in around 1100. I can take a loaded trailer & accelerate to 60 mph faster than most drivers can with an EMPTY tailer! It's all about using the torque that's available to you, with minimal pressure on the throttle. I rarely push the pedal more than an inch or so :)

FLS & FTS settings can be found in the Cat ET program, open the ECM configuration tool & scroll to the bottom...last line. Inside here is where you can see the Full Load Settings and Full Torque Settings. Cat normally "locks" these settings, you will probably see a "key" icon next to them. You have to be a "full-customer" of the Cat ET program & have a factory password from Cat to change these settings.

You really need to turn the rpm settings up on the lower gears a little bit...if they're set at 1500, they start cutting back fuel at 1400. When we got these trucks, they were set at 1600, but they started to cut the fuel around 1500 & made it hard to "control" the next shift & be smooth. Consider setting it at 1700 & explain to the drivers that they need to shift at 1500. That way they never "run out" of pedal :)
rufus

Albany, NY

#9 Jul 25, 2012
That is interesting. Ya I say the fts and fls under the personality module. So what do they mean? It gives you a range from -127 to 128. I see guys that have a pmc of 46 and then a fts28 and fps of 6 or something. I just made those up but I see guys talking about it and I didn't know what the numbers represent.
Ken

Marion, IN

#11 Jul 31, 2012
rufus wrote:
That is interesting. Ya I say the fts and fls under the personality module. So what do they mean? It gives you a range from -127 to 128. I see guys that have a pmc of 46 and then a fts28 and fps of 6 or something. I just made those up but I see guys talking about it and I didn't know what the numbers represent.
The fuel pressure normally runs 70 to 75 @ an idle, 100 psi @ 1800 rpm. I have some trucks that show 65-68 @ an idle, not enough to "shim" the fuel transfer pump. When you check it on the return line, you're seeing the "actual" fuel pressure inside the head at the injectors. Firing order is the same, intake is .015, exhaust .030, jakes are .030 and the IVA pistons are .020. You can set the jakes & IVA at the same time you're adjusting the valves, on the same cylinders. I always "back-off" those two a little bit BEFORE I adjust the intake & exhaust valves.

The o-rings are as follows...there are 3 o-rings where the oil tubes bolt down to the head spacer. This is the oil supply to each Jake/IVA assembly. There are two bolts holding them down, with a 3/8 head. After you remove these two bolts, grasp the little tube and lift straight up. It will "slide" off of the Jake/IVA housing, and you will see two more o-rings inside each sleeve. You will need to order 3 o-rings part# 6v5759 and 6 o-rings part# 0618639. Hope this helps!
rufus

Albany, NY

#12 Jul 31, 2012
Ken thanks for the info and I remember reading a different post when setting the iva pistons I have to pinch it harder and allow the oil to push out.
rufus

Albany, NY

#13 Aug 10, 2012
I have a couple different questions. First, on a C-15 it is reading that the calibration is off between the two speed sensors. How do I calibrate that?
Second, I have a 3406E 1LW28926 that is reading:
110-0 High coolant 255 occ
174-0 High Fuel Temp 255 occ
110-11 Very high coolant temp 120 occ
These are in about 7000hrs from first to last

I drove it the other day and the dash gauges didn't read hot 190 I guess. It did run get hot but the engine fan kicked on a nd it recovered quickly. So I don't believe that it is running hot. I guess I am wondering if there is a different issue that could be causing the ecm to be getting faulty measurements.

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#14 Aug 11, 2012
rufus wrote:
I have a couple different questions. First, on a C-15 it is reading that the calibration is off between the two speed sensors. How do I calibrate that?
Second, I have a 3406E 1LW28926 that is reading:
110-0 High coolant 255 occ
174-0 High Fuel Temp 255 occ
110-11 Very high coolant temp 120 occ
These are in about 7000hrs from first to last
I drove it the other day and the dash gauges didn't read hot 190 I guess. It did run get hot but the engine fan kicked on a nd it recovered quickly. So I don't believe that it is running hot. I guess I am wondering if there is a different issue that could be causing the ecm to be getting faulty measurements.
Do your trucks use two speed sensors mounted on the transmission? Our transmission housings have a place to mount both the "push-in" kind, and also the "threaded" kind. We only use one speed sensor to communicate with the ECM & Speedometer. You can calibrate the sensors using the Cat ET program, open the Configuration Tool and look under "Vehicle Speed" settings. There will be a 5 digit number showing for "speed sensor calibration". If the ECM is recognizing both speed sensors, then the second sensor should have a 5 digit number showing, as well. Make sure that both numbers are the same!

On the 3406-E, the wires for the coolant sensor & fuel temp sensor travel side-by-side in the same harness. It's possible that they are "shorting-out" somewhere, causing the faulty readings. Or, some driver has been using "resistors" to "fool" the ECM on the fuel temp wires to create more boost pressure & get more fuel to the injectors...
rufus

Albany, NY

#15 Aug 16, 2012
Ken good idea on the wires shorting out. I will check out the harness. Sorry I wasn't clear on the "speed sensor" thing. I mean the one on the cam and the one on the crank. It says they need to be sync.
rufus

Albany, NY

#16 Aug 18, 2012
What is code 100-3 oil pressure voltage high. Is this the crank oil pressure or something to do with the overhead

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#17 Aug 19, 2012
rufus wrote:
What is code 100-3 oil pressure voltage high. Is this the crank oil pressure or something to do with the overhead
100-3 is the main oil pressure sending unit on the side of the engine. 385-3 is the code for the IVA oil pressure sending unit on top of the head. Whenever I get this code of "high voltage", I know the sensor has failed. Replace the sensor & clear the code from ECM :)

On the crank & cam sensor...when the ECM can read one, but not the other, you will get the "sync" message. If the engine will run, use the Cat ET program to "see" the rpm reading from each sensor individually. The rpm reading you normally see on the right, when you have the ET program open, is from the cam. The tach inside the truck gets it's info from the cam sensor, as well. Is the tach working properly & showing an rpm reading?
rufus

New York, NY

#18 Aug 19, 2012
Thanks again Ken. the Tach does work in that truck with the sync issue. I will poke around in the et to find where I can read the individual sensor readings. I am guessing that its under one of the status groups?
Question on the 385-3. I have had one truck that we changed the sensor and still had the same code. I talked to our local pete dealer and they said one wire is common(ground), one is the power 5v and one is signal or used to jump the sensor if the ecm detects it isn't functioning correctly and that is 9 or 12v can't remember. Anyway on that truck it turned out that the wires had desintegrated because of the heat from the turbo. Have you had that happen? If that code is thrown will the iva's stop working? I mean assuming there is 42psi but the sensor is not reading for one reason or another. Does the ecm still send power to the ivas?
Next question: on one truck cyl#4 iva keeps showing high voltage then not responding. i ran the test where it sends power to each one individually and I can hear it click. But the engine is cold. I didn't know if when it gets hot of something changes because in the shop everything works then when the driver takes it out it fails on the road.(this engine also had the 385-3) the plug going into #4 iva has fallen apart so all i have are the two sockets that go over the pins. Is there anyway to get new ends for these? By the way when it works its great he gets 52psi boost. As soon as it fails he is down below 40
Thanks

“Cat & Cummins ECM programs”

Since: Jun 12

Marion, IN

#19 Aug 20, 2012
The IVA oil sending unit has an independent ground all the way to the ECM. But the IVA Control solenoid shares a ground with the Coolant Diverter Valve. The fuel temp sending unit, coolant temp & intake air temp share a ground. I have had to replace the wires going to the coolant diverter valve on EVERY truck we have...they were melted together when we got them! I made a new harness that comes out under the alternator & travels along the frame rail to the valve...no more burnt wires :)

Whenever an IVA solenoid fails, the ECM cuts the power to the rest of them by 20 to 50%, causing a big drop in boost pressure. You can buy new plug ends from Cat, use a paperclip to "release" the new metal pins from inside the plastic plug & "slide" your existing pins into the housing til they lock in place. No cutting or splicing of wires that way!

I have had some solenoids that show OK when tested cold, then they started throwing codes during operation. I had one last week that was showing codes for 3 & 4, ran the VVA test & all solenoids showed OK...started the truck & immediately threw codes again. Opened valve cover & discovered that two of the studs holding down the Jake / IVA housing were broken, allowing the housing to move enough that the oil supply tube had shifted on the housing & the o-rings were leaking oil...causing insufficient oil pressure to VVA 3 & 4.

Whenever you see both solenoids on the same housing coding out, check the bolts & check the 3 0-rings on the oil supply tube to that particular housing. On the truck with the #4 VVA coding when hot, change the solenoid, if you haven't already done so, & see if it codes out again. Save your core in case the new one shows the same code!

Give me an e-mail address & I'll send you a complete, easy to read schematic for these engines, shows every wire & harness from sensor to ECM, all the ECM pins, head connector pins, everything. I can also send you many other files related to these engines :)
rufus

New York, NY

#20 Aug 20, 2012
Ken Thanks my email is [email protected] Another question that I thought of today was droop. I forgot about it but then I saw it today in dddl 6.45 so I am guessing it means something. I remember seeing it in the configuration on cat et. Thanks for all the above helpful knowledge I certainly don't get these kind of answers from the local cat dealer.
Ken

Marion, IN

#21 Aug 23, 2012
Rufus, I sent 9 files to the e-mail address you listed above, hope you received them OK!

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