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Check ECU Brake Module Error


kidder

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Hey Everyone,

 

Truck has been sitting about a 2 weeks or so (turned the batter switch off and put the tender on).

 

Hoped into the truck this morning - as I needed to move it so that a trades person could to work around our shop. Truck started right up so I let it sit to warm up. Came back about 20min. later opened the door and as I am opening the door - the trucked alarmed and shutdown and through "ECU Brake Module Error - check on next stop". I don't think the door openning had anything to do with it - but it sure was weird timing.

 

So I pushed in the brake, put it in gear and moved about 10 feet and the same error was thrown and the truck shutdown. Truck started back up ... moved it about 50 ft (where I wanted to move it to) and then error was thrown again and the truck shutdown.

 

Obviously, wouldn't want this to happen as I am going down the road. The truck has never thrown any errors like this before - has anyone seen anything like this?

 

Any thoughts/ideas/suggestions?

 

Thanks,

Curt

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Is it possible to shut the engine/exhaust brake completely off on a Volvo engine? It is with a Jake brake, but I understand that the engine braking is more "integral" on Volvo engines.

 

The reason that I ask is that ECU is the Engine Control Unit, and the only braking that could involve the ECU would be the engine braking system. If it's on right now, try shutting it off (or turning it on if it's currently shut off) to see if makes a difference in the error condition.

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Is it possible to shut the engine/exhaust brake completely off on a Volvo engine? It is with a Jake brake, but I understand that the engine braking is more "integral" on Volvo engines.

 

The reason that I ask is that ECU is the Engine Control Unit, and the only braking that could involve the ECU would be the engine braking system. If it's on right now, try shutting it off (or turning it on if it's currently shut off) to see if makes a difference in the error condition.

Phil,

 

It was a good thought - but the Jake was off.

 

C

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Kidder - the exhaust brake was on. The switch may have been off, but the exhaust brake is part of the warm up circuit. Once the air builds up, that hissing sound that you should hear is the exhaust brake closing and the engine working against it. If you have the DID on fuel use, you'll also notice that the engine is using more fuel to fight against it.

 

Diesel engines with no load, can do what is called wet stacking, unburned fuel in the exhaust. Volvo, uses the exhaust brake to provide load, and keep the engine loaded and warm. Once it is at ~170, the exhaust brake opens and closes to maintain the engines' operating temp. Once you start loading the engine, driving or pulling something, there is enough load and the exhaust brake switch then becomes "operational". ie used for real braking.

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Have you looked for the specific code it threw? That will tell you more than the generic message on the main screen.

Big5er,

 

So I went out to get the codes and thought I would start the truck up again. Started right up, started to warm up - ran for about 5 min. then I noticed the idle come right down (it almost stopped) but didn't. It stayed at idle for a minute or two and the truck shutdown. I tried to start the truck and again, and it idled for about 3 seconds and then shutdown.

 

I cleaned out all the error codes (I haven't done that in a long time). Tried to start it - same shutdown happened and threw the brake error again. Here is the message and codes:

 

Engine ECU

Engine ECU request engine brake torque communication error

MID 128 PPID86 FMI 9

 

Brake ECU

SAE J1939

MID 136 SID 231 FMI 9

Communication Error

 

The other that happened at the very end was the ABS light came on (yellow - bottom right) - and wouldn't go out (even after I recycled the ignition). The truck has been singled and when I had that done obviously had the sensors removed - but that was over 4 years ago.

 

One other thing to note, I did have one of the brake rear brake chambers replaced about 3 weeks ago as it was shot. I watched the guy do the repair and it looked totally harmless (ie. he didn't really mess with anything other then replacing the chamber).

 

Thanks for the help everyone.

 

The nice thing is that is winter up here now - so no plans to go anywhere. The bad thing is that it is winter up here and having to work on the truck in -1 ... sucks.

 

C

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Kidder,

Ours has done the same.... We so far have found out the dash cluster malfunctioned and threw a direct hit to the alt,. trans ecm, and they are not sure what else. It also fried 3 out of 4 batteries, and some other little black box that is under (imbedded ) the dash. We are confidant that it will be repaired , but it again sounded just like what you are going through. I didn't go to a Volvo dealer due to hourly labor costs , and a family member that works in the parts industry recommended this facility . Please if you would keep us all updated and I will try to do the same.

 

Happy Thanksgiving to all. !

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Kidder,

Ours has done the same.... We so far have found out the dash cluster malfunctioned and threw a direct hit to the alt,. trans ecm, and they are not sure what else. It also fried 3 out of 4 batteries, and some other little black box that is under (imbedded ) the dash. We are confidant that it will be repaired , but it again sounded just like what you are going through. I didn't go to a Volvo dealer due to hourly labor costs , and a family member that works in the parts industry recommended this facility . Please if you would keep us all updated and I will try to do the same.

 

Happy Thanksgiving to all. !

Dam!

 

That really sucks. If it is that severe for our truck ... I will probably just have it towed to the auto wrecker - minus the hitch, Jackoloppe, backup camera et al.

 

Our truck is a 2004 and although nice - I suspect a repair like yours would be worth more then the truck.

 

I also thought of trying to find someone else who could look at it other then Volvo. But my thought was/is that Volvo should be able to diagnose it a lot faster then a none Volvo mechanic. As I mentioned above, I am not too stressed as it is sitting in a good spot in the driveway ... versus being out on the road.

 

Will let you know what I find out.

 

C

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Curt, time to step back, and take a breath or 2. Chances are all you have is an electrical gremlin. First thing that is always recommended here is to start checking the ground/negative cables on the batteries and in your case the dash clusters. Second thing is to call a local shop and see if they work on Volvo's or if they know who does without taking it to the dealer.

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try resetting the gremlins....

 

disconnect your batteries and let it sit a half hour or more and reconnect batteries...

 

this:

 

Engine ECU
Engine ECU request engine brake torque communication error
MID 128 PPID86 FMI 9

 

Brake ECU
SAE J1939

MID 136 SID 231 FMI 9
Communication Error

 

suggests you have the data link wires (theres a pair of them) thats either grounded or ones broken somewhere.

the Datalink is a buss that all the computers talk on to each other..... OR the engine brake ecm died.

 

it might not be all that bad yet...

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HI Everyone,

 

Thanks for all the great ideas. Here was my testing and the results:

1) I have a cut off switch to the batteries, so I turned off power to the truck and let it sit for an hour. Went outside, turn the battery bank back on - truck turns over no start :(
2) I checked all the relevant fuses, reseated most, truck turns over - no start :(

3) Checked the negative terminals on the battery - all seems super solid - but did a quick check - all were solid - truck turns over - no start :(
4) For sh*ts and giggles I decided to check all the positive terminals on the battery - the absolute most difficult one to reach - the one wire attached to it - wiggled ... I was like - this can't be the issue. Took it apart, put some dielectric grease on, tightened up snug, turn the key - BAM - truck fired up!!!!

So huge learning experience and this is not the first time a connection to a battery has been the culprit. First thing to check if anything goes wrong with the truck - make sure the batteries and ALL of it's connections are good!!!

 

My ABS light continues to be on - so at a min. I will take it into a shop to see what is up with that - as it has never been on since I got the truck. I know Volvo turned it off for the axle that was removed - so something still could be wrong with the brake ECU.

 

Question - is changing out a brake ECU something us 'in home' mechanics can change or is better to let the Volvo guys do it?

 

Thanks everyone. Love this forum - so much knowledge.

 

C

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I have found if I use my "trailer brake valve" ( red knob) to use air from the truck to inflate my tires and if I forget to reset the valve to "off" and drive away the "abs" light will be lit. To reset the light I usually need to reset the knob to "off" and drive a bit. Might be something to try.

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check your brake sensors on all axles. if ones a bit loose or misaligned can cause a error from the ABS ECU.

 

the ABS ECU is on the cross-member under the sleeper. as long as you get a identical model , its a un-plug and unbolt from the frame and install the new one.

you may or may not have to program the new one if your singled.

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I have found if I use my "trailer brake valve" ( red knob) to use air from the truck to inflate my tires and if I forget to reset the valve to "off" and drive away the "abs" light will be lit. To reset the light I usually need to reset the knob to "off" and drive a bit. Might be something to try.

 

When I pulled the ABS fuse my ABS amber light stayed on till I drove it, not sure at what speed or distance, but was in town, at the first red light I came to it was off.

Worth a test drive before you do anything else.

 

Roger

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So huge learning experience and this is not the first time a connection to a battery has been the culprit. First thing to check if anything goes wrong with the truck - make sure the batteries and ALL of it's connections are good!!!

 

Funny you bring this up. In the past couple of weeks, I've had battery terminal issues on the Volvo, the Mack, and one of my tractors. All had the nuts loose, some not even finger tight, for no apparent reason. I know they had all been tightened recently, so how/why did they loosen? Never had this before.

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Turn your key on and see if both rear sensors are clicking for the normal test. If not then one of them is bad or not registering. It could be the sensor, a connection , wiring or the trans Ecm.

Since someone was working in the brake area they may have accidentally did something to cause the connection problem.

Also check the cab grounds. They should 3 of them on right and 3 on the left side of the firewall.

 

Keep us posted as to what is happening. Vern

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Turn your key on and see if both rear sensors are clicking for the normal test. If not then one of them is bad or not registering. It could be the sensor, a connection , wiring or the trans Ecm.

Since someone was working in the brake area they may have accidentally did something to cause the connection problem.

Also check the cab grounds. They should 3 of them on right and 3 on the left side of the firewall.

 

Keep us posted as to what is happening. Vern

Ok - dumb question - but where are the rear sensors? Can easily check on the firewall both sides.

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When you turn the key on you should here each wheel sensor click in a sequence. It's not the wheel sensor that is clicking,but the valve that will release the air to the brakes for the anti lock brakes system. The wheel speed sensor, modulating valve, cab or trans ecm and wiring harness all need to be working properly to sense what is happening. So there is probably one of those items not working properly and showing you the code.

You need to hear one for each wheel.

If there is not one for each wheel then that should be the wheel that has the problem.

The cab grounds can be a problem with many different things and possibly your problem also.

If one modulating valve is working and not the other on the rear axle you might switch the wiring from one valve to the other. That should tell if it is the valve is bad on something back towards the Ecm is the problem.

As for the wheel speed sensor working you need to jack the tire off the ground on the side in question. Disconnect the speed sensor wire, connect a volt meter to the wire terminals, rotate the tire at a good speed and look for a few volts.

 

 

That should give a good idea what is happening.

 

 

Safe Travels, Vern

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