Midland Grau ABS system

Topic: Midland Grau ABS system (Read 3681 times) previous topic - next topic

Midland Grau ABS system

December 03, 2011, 04:58:14 pm

Ok, I have a code 0.2 on the ECU that says" B sensor open or short circuit, axle A"
I take that to mean right front tire sensor is bad. Long story short is that I changed that sensor with a new one and still get the same reading??? Have read all I can find about the ABS system trouble shooting on Barrys site and other places. BTW, the old sensor read 1.1 ohms. Also the code guides are different for the Midland Grau system than for the Meriator Wabco system. Took the coach to Valley Diesel who said they did ABS work but didn't have the right equipment to access the ECU unit on the Midland Grau! HUH! So the tech didn't do much more than I had before I took it to them. Any and all comments would be greatly appreciated.

Re: Midland Grau ABS system

Reply #1 – December 05, 2011, 08:18:59 pm

After 4 hours of trouble shooting and phone calls, my saga is over.......almost!
Long story short is the ECU is bad!!! I've been told that Midland Grau is no longer in business, and my type of unit is not avaiable any more

called FOT to see what my options are regarding replacing or repairing the bad board.

Re: Midland Grau ABS system

Reply #2 – December 05, 2011, 08:23:18 pm

Richard,

The loss of the ABS system does not affect the operation the coach or braking system in anyway other than the ABS will not operate. So repair at your convenience. Just know, no ABS till then.

Re: Midland Grau ABS system

Reply #3 – December 05, 2011, 08:30:35 pm

Quote from: rbark – December 05, 2011, 08:18:59 pm

After 4 hours of trouble shooting and phone calls, my saga is over.......almost!
Long story short is the ECU is bad!!! I've been told that Midland Grau is no longer in business,

I did a Google search, and it appears Haldex acquired Midland Grau. Don't know if that helps at all, but it might be a place to start. I also found the following website which lists some Midland/Haldex parts

Six States Distributors - Supplier Midland Haldex Brake Components

Also in the search (Midland ABS ECU) I found this ECU assembly. Don't know if it's the right one, but the vendor might be another to check:

ECU Assy PLC Selector, AL919338, Haldex-Midland

-M

Re: Midland Grau ABS system

Reply #4 – December 05, 2011, 11:56:29 pm

That is great Steve and Michelle! I will do some calling first thing tomorrow. I've also heard that Dinosaur Electronics does repair work on circuit boards. Thanks for the tip!
Richard & Betty

Re: Midland Grau ABS system

Reply #5 – December 06, 2011, 09:06:59 am

Richard, My 95 280 has a Midland Grau DGX system which may be the same as yours. It is obsolete. When I had problems I was finally able to contact them with the number in the post below. I cannot recall the engineers name but he was more than helpful.

http://www.foreforums.com/index.php?action=search2

Good luck

Re: Midland Grau ABS system

Reply #6 – December 06, 2011, 09:11:16 am

Richard, Also see these posts about ABS.

ABS Final ( I hope )

Gary B

Re: Midland Grau ABS system

Reply #7 – December 06, 2011, 07:29:39 pm

Steve & Michelle,
Called both those sites today and neither could help. My unit is obsolete so I'm going outside the box. Sent the ECU to Dinosaur Electronics in Linclon City,Or. They do repairs on circuit boards of all types. Their web site is the same as their name. Talked to the owner, Guy, and he said he'd take a look at it and see if it was repairable. They also repair the Duo- Therm units and Dometic boards along with other stuff for the older coaches.

Gary, I could not open that link you sent.

Re: Midland Grau ABS system

Reply #8 – December 06, 2011, 11:00:25 pm

Hi Richard,
You might ask Jim Frerichs about the board repair. He is an electronics repairman/guru. He is a member of our group. He does repairs on some Aqua_Hot "so called" non repairable electronic parts. He may know something about your problem. Best of luck.
Raymond Jordan

Re: Midland Grau ABS system

Reply #9 – December 06, 2011, 11:22:44 pm

Raymond, thank you! I'll contact him as soon as I can. Driving to Palm Desert in the morning.

Re: Midland Grau ABS system

Reply #10 – December 07, 2011, 08:41:10 am

Richard, Here is the post from the old Yahoo group.

Yahoo Message Number: 17018
As I posted Previously my ABS lite was on and in addition the retarder quit.
After a lot of help from Midland ( and little from FT) the problem was diagnosed as a bad wheel sensor, replaced sensor ( $65) problem fixed, Transmission operates normally. Perhaps not all FT's are configured the same but I can tell you for sure that a failed ABS sensor will shut down Transmission retarder if coach is equipped with a DGX generation Midland Grau ABS system. This DGX type is obsolete and no longer made, sensors are fairly common but part numbers are confusing. The SHORT SENSOR type with 90 degree wire is a Meritor R955342, there are two of these one has an 18" pigtail and the other has a FIVE foot piftail, both will work the same. FWIW, If you have an ABS lite on the diagnoses is fairly simple, pull cover off box and use an OHMMeter to check each sensor, in general the sensor will have two wires, one brown, one black. If sensors OHM out you will have to look further. Midland phone number is 816-891-2470 ask for ABS tech.

Gary B 95 U280

Re: Midland Grau ABS system

Reply #11 – December 07, 2011, 08:50:51 am

Richard, I have attached an ABS manual, it may be useful.
Sorry the link did not work. The link is working now.
Gary B

Re: Midland Grau ABS system

Reply #12 – December 09, 2011, 02:17:04 am

Gary, that IS my unit! Looking at the drawing of the ECU,it is the same as I have. This could be just what I need. Thank you sooo much. I'll contact Thames and go from there.
Richard & Betty

Re: Midland Grau ABS system

Reply #13 – January 04, 2012, 02:15:24 pm

I am wondering if you were able to get your abs repaired as I am having trouble with mine. Any help will be appreciated. Thanks

Re: Midland Grau ABS system

Reply #14 – January 04, 2012, 02:44:37 pm

Quote from: red tractor – January 04, 2012, 02:15:24 pm

I am wondering if you were able to get your abs repaired as I am having trouble with mine.

With the 2003, it should be the same unit we and Barry B. have (and a few others). What are the symptoms and what diagnostic blink code(s) are you getting? Barry's got the Wabco Meritor magic blink code decoder ring on his site

ABS Troubleshooting

ABS Troubleshooting Codes

Michelle

Re: Midland Grau ABS system

Reply #15 – January 04, 2012, 07:30:38 pm

Now I am curious. Is there any interaction between the ABS and the retarder? Does the ABS modulation of the air brakes also cut off the retarder braking?

Re: Midland Grau ABS system

Reply #16 – January 04, 2012, 08:50:51 pm

Quote from: Tom Lang – January 04, 2012, 07:30:38 pm

Now I am curious. Is there any interaction between the ABS and the retarder? Does the ABS modulation of the air brakes also cut off the retarder braking?

The ECU sends signals to the ABS malfunction indicator lamp or blink code lamp to communicate ABS faults. It also sends signals to the retarder control to disengage the retarder when the ABS is working. When the ABS stops modulating the brake pressure, the ECU permits retarder use once again.

Re: Midland Grau ABS system

Reply #17 – January 04, 2012, 09:30:48 pm

the abs is fine on my 03 coach, it is my 98 that has a problem. forgot that it showed 03 Everyone should have 2 foretravels?

Re: Midland Grau ABS system

Reply #18 – January 04, 2012, 10:22:22 pm

Quote from: red tractor – January 04, 2012, 09:30:48 pm

the abs is fine on my 03 coach, it is my 98 that has a problem. forgot that it showed 03 Everyone should have 2 foretravels?

One for even days, one for odd? LOL

Re: Midland Grau ABS system

Reply #19 – January 05, 2012, 09:48:28 am

Quote from: Barry Beam – January 04, 2012, 08:50:51 pm

The ECU sends signals to the ABS malfunction indicator lamp or blink code lamp to communicate ABS faults. It also sends signals to the retarder control to disengage the retarder when the ABS is working. When the ABS stops modulating the brake pressure, the ECU permits retarder use once again.

That being the case, it should be relatively safe to use the retarder in the rain.

Re: Midland Grau ABS system

Reply #20 – January 05, 2012, 11:15:51 am

Quote from: Tom Lang – January 05, 2012, 09:48:28 am

That being the case, it should be relatively safe to use the retarder in the rain.

Not according to Foretravel or:
www.fmcsa.dot.gov/about/outreach/bus/safety-technologies.htm#8

WARNINGS

DO NOT USE A RETARDER WHILE DRIVING ON WET, ICY, OR SLIPPERY ROADS. DOING SO CAN CAUSE A LOSS OF CONTROL.

IN COLD WEATHER, TURN THE RETARDER OFF WHEN APPROACHING BRIDGE DECKS, ON-RAMPS, OR EXIT RAMPS.

DURING SLIPPERY CONDITIONS, TURN THE RETARDER OFF USING THE MASTER CONTROL (ON/OFF) SWITCH LEVER.

IF YOU EXPERIENCE A LOSS OF DIRECTIONAL CONTROL, IMMEDIATELY TURN OFF THE RETARDER.

IMPORTANT POINTS ABOUT RETARDERS

The master control (ON/OFF) switch is usually accompanied by a light which indicates the system is activated. Periodically check to verify the retarder is functioning by activating the master control switch at closed throttle only. Throttle activation automatically deactivates the retarder.

The retarder is not a replacement for your brakes. However, it can be used to slow down or maintain motorcoach speed during most highway operations. Retarders help to extend brake life and prevent brake fade.

Remember that the retarder only brakes the drive axle and cannot detect slippery roads or other environmental hazards. It is possible for the rear of the motorcoach to lose traction on wet, icy, or slippery roads when the retarder is applied. Do not use the retarder during such conditions.

To minimize the risk of brake fade, use the retarder with the proper transmission gear for the slope and length of the grade and the speed of the motorcoach.

With some motorcoaches, the ABS is designed to deactivate the retarder when wheel-lock starts. Panic stops, wet surfaces, and driver over-reaction may activate the ABS and deactivate (turn off) the retarder.

Re: Midland Grau ABS system

Reply #21 – January 05, 2012, 11:23:21 am

Intereting. This sounds like the legal department writing "do not operate the toaster while taking a bath". So, is the programming of the ECU such that the retarder is momentarity turned off by a "no traction" condition in the ABS module? Then the retarder is returned to the full "on" state after the ABS has no more traction loss condition?

Re: Midland Grau ABS system

Reply #22 – January 05, 2012, 11:25:34 am

With some motorcoaches, the ABS is designed to deactivate the retarder when wheel-lock starts. Panic stops, wet surfaces, and driver over-reaction may activate the ABS and deactivate (turn off) the retarder.

Assuming our Foretravel motorcoaches are included in the above mentioned group, the coach would be smart enough to turn off the retarder under such conditions, even if the driver forgets to do so.

Affiliate Notice