Brake Retarder Status

I have the small gauge for telling me when the engine brake is in operation. The gauge works great, however I would like to reverse the colors. Now when in operation the color is GREEN and when not in operation its color is RED. I would like to reverse the colors, have the gauge display GREEN for non operation and RED when in operation. This is on a Mercedes Benz engine with (CTV) Constant Throttle Valve engine brake, one stage.
Has anyone done this?

Back to the top, I attempted

Back to the top, I attempted over the weekend to play with the numerical setting for the low RED setting to no avail. Has anyone tried and had success with reversing the colors?

Re:Brake Retarder Status

What PID are you monitoring??

I might be able to look up the needed information.

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

Mark, PID set to 121 Guage

Mark,

PID set to 121

Guage settings same as "cruise status"
Gauge minimum = 0
Low Red line = 1
High Red line = 150
Guage max = 150
Low Yellow = 2
High Yellow = 150

Thanks

Re:Mark, PID set to 121 Guage

I have not forgot about you..

Do you get any data on PID 47??? This PID might be easer to get the Status you are looking for.

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

I have a PID 40, Engine Retarder Switch

Mark,

This MB engine does not have an exhaust brake (PID 47, It does have the PID 40, Engine retarder switch). Some months ago I did try this PID just do not remember the results at this time. I am sure if I had good results I would be using it, instead of PID 121. The MB 926 engine was initially shipped with just the (CTV) constant throttle valve (engine brake). This is the engine I have. The later MB 926 version had both the (CTV) and the exhaust brake, there for it had two stages of braking. The CTV and the Exhaust brake.

Re:I have a PID 40, Engine Retarder Switch

PID 40 is simular to PID 47, in that the first two bit are the exact same status.

PID 40, 47 and 121 are all 1 Byte (8 Bits).

Do you have examples of values from PID 40 and 121 while the Brake is active and not active??

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

Examples, No not at this time

It will be a couple of weeks before I am able to get out on the road again. I will get info at tht time. Thanks

Brake retarder

Mark,

Is it possible to add an indicator for the Pac Brake status to my existing VMSpc display?

Carry on, regardless

Re:Brake retarder

Our experience with the Pac Brake system is, the Engine is not aware of it. Because of that, it is not reported by ECM.

Your engine might be different. Look to see if you get any data from PIDs 40, 47 or 121.

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

Mark, I just checked on this

Mark,

I just checked on this information. I set up two new simple guages, one for Cruise Control Switch Status, RED = 192, YELLOW = 208 and GREEN = 209. On the Engine Retarder Status, RED = 192, GREEN = ?. I did not take the coach out for a run to check the GREEN numbers, would it be like the other switch and be 209?
Any ideas on how to invert the displayed colors on the Engine Retarder Status? Disengaged = GREEN and Engaged = RED.

I have used this same

I have used this same program on a Cat 3126 with the Jacobs Extarder, a Cummins ISB with a Pac Brake and now the Mercedes Benz with the CTV (Constant Throttle Valves).
Regarding the two exhaust brakes (PID 47), (Cat and Cummins)the ECM electrically controls a air solenoid which supplies air pressure to move the exhaust brake butterfly valve. The normal small guage display would be RED for normal operation and GREEN when the exhaust brake is applied. The same display I get with the CTV, which I am trying to invert the displayed colors on.

Mark, Disregard the

Mark,

Disregard the information on the Engine Retarder Status. I had the PID set for the Engine Retarder Switch (PID 40) instead of the Engine Retarder Status (PID 121). I went back to the coach and reset the PID value and it only returned 0 for a value, even with the ignition on. I'll try to take it out for a run in a day or two. I will get back with the results.

Just got back from a test

Just got back from a test run with three value guages set up for PID 40, PID 47 and PID 121. During ENGINE BRAKING the ECM did not return any change in display value on the PID 40 or PID 47 guages.
On my PID 121 Guage, Engine Retarder Status. When the guage is RED the value is 0. When the guage is GREEN the value is 128.
With this information, can you tell me how to set the guage up to display GREEN when the ENGINE BRAKE is DISENGAGED, and RED when the ENGINE BRAKE is ENGAGED, the reverse of current operation?

Thanks,

Re:Just got back from a test

Excellent!!! You are in "luck"!!!

The Byte of Data for PID 121 shows 6 of the Bits are used, 2 bits are Reserved. I was worried your engine will be reporting something on the first 5 bits, but your report indicates they are ALWAYS ZERO, which makes what you want to do, so much simpler, since VMSpc does not support any sort of Bit Masking.

PID 121 is Engine Retarder Status, and Bit 8 is 1=on/0=off. Which is reported on VMSpc as 128=on and 0=off.
So, using the Tachometer as a reference (Higher Value is RED, Lower Value is GREEN), I would try something like:
Low Red Line 0
High Red Line 128
Low Yellow Line 0
High Yellow Line 128

The RED status should take priorty over the YELLOW status, but if you see Yellow instead of Red, change:
High Yellow Line to 64.

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

Thanks Mark, I'll give it a

Thanks Mark, I'll give it a try and report back.

Retarder Status

My coach is a 2000 Foretravel with Cummins M11 engine, Allison HD4060R transmission.

It is equipped with a 6-position joystick transmission retarder

I have checked the following PID’s and the readings do not change upon application of the retarder: 40, 47 and 121

It would be ok to get an indicator light indicating that the retarder is on (I always forget to turn it off!). It would be wonderful (and hot stuff) to get a number signifying what position the joystick is on (0-6).

Anyone have any thoughts on how to accomplish this?

- Roger Berke -

Re:Retarder Status

Is this an Allison "transmission retarder" or another manufactures "transmission retarder"??

The "Transmission" might report the Retarder Status itself, rather than the "Engine" reporting Retarder Status.

Mark Overholser

===================================================================
Mark D. Overholser
Engineering Technician
SilverLeaf Electronics Inc.
2490 Ferry Street SW
Albany, OR 97322

888-741-0259
541-967-8111
541-967-8988 (fax)

RE: Retarder Status

I think that another company makes the joystick, but it interfaces directly with the Allison transmission.

I think that you telling me is the VMSpc only receives information from the engine and not from the transmission. No joystick retarder status information is displayable.

- Roger Berke -

Roger, I did a little

Roger,

I did a little research on the Allison website. I am assuming that your transmission has second generation controls. If you go to the Allison website and look under transmission by series and then HD 4060R you can download a few manuals. The owners manual makes reference to the MANUAL 6 position joystick. With a little research you may be able to find a output on your transmission which will allow you to mount a light on your dash. The little, I read on the 6 position joystick makes me believe that the positions 1 - 6 are progressivly more retarding the larger the number the most retarding. This is a hydraulic retarder, when selected a oil chamber is filled and pressurized and oil is directed against a vane which retards the transmission output shaft. Click on this link.
http://www.allisontransmission.com/publications/pubs/OM2157EN.jsp

RE: Retarder Status

Ted

Thanks for the information and the link to Allison Transmission.

The information that you provided is correct.

I DO have a light that illuminates when retarder is “retarding”, however it is outside of my line of sight (on the retarder on/off switch on the control panel beside my seat).

I was hoping that the VMSpc would be able to provide this information, because it tells me everything else!

- Roger Berke -

Roger, It should not be a

Roger,

It should not be a big problem to install another light in your field of vision, or move the power from the exiting light to a new in dash place.
Of course, I agree about the VMSpc. Check your PID's to see if some other number is reporting your retarder operation.

PID 121

I have a simple gauge that uses PID 121.

It works as above. With the retarder off it indicates a "green" dot and displays the word "OFF". When the status of the retarder changes (turns on) the dot goes "red" and the display goes to the word "error".

It responds correctly to what the exhaust brake is doing, but...

Now, how can I get the gauge to display "ON" instead of "Error" when PID 121 changes to engaged?