Another Red Triangle of Death.

[Bear]

Last Sunday I had the red triangle plus the brake failure lamp flashing fast while riding. This was at the end of a 150 mile day, with no prior problems. I switched off the engine, waited a few seconds, then restarted it and all was well. Sixty miles went OK yesterday. I has the same thing twice today. The first time I restarted the engine and the fault went away. The second time I didn't bother trying. As far as I could tell the front brake still has servo-assistance but the rear hasn't while the error shows. At home, I checked that both brake light switches work OK (they do) and that none of the pads were worn. All seemed OK so I took the tank off to check the reservoirs tucked away underneath. Assuming I checked the correct items (10mm allen key to open them and DOT4 brake fluid stamped next to them) the level in each seemed OK. I had the rear wheel sensor out about 1500 miles ago to change the FD oil but since the speedometer still works I cant see it as a problem. I'm now stuck for ideas until the dealers open on Tuesday so any suggestions would be gratefully received. I should have said at the beginning that the bike is a 2006 1200 with servo-assisted ABS.

 

[Pukmeister]

Bit of a bummer, sounds like you have done your homework and done all the right checks. Only other thing could be a worn out battery or alternator fault causing low voltage to the ABS controller module causing faults, or a dodgy wiring loom connection under the tank.

Can you get hold of a diagnostic tester eg GS911? Maybe there are fault codes that could help in the diagnosis. Failing that, its off to the dealers.

 

[Bear]

The battery is a BMW item and is 18 months old. The starter motor turns properly so I woulod assume that the battery is in reasonable condition. The connections to it aree clean and tight. I looked at the connectors on top of the fluid reservoirs in case corrosion was causing a problem but both were clean. I doubt if the alternator is faulty because I could restart the engine immediatley after the problem and the tiny battery wouldn't hold hold up the ignition and starter motor for long. Unless someone in south Cheshire has a GS911 and a fondness for beer similar to my own it's a phone call on Tuesday morning.

 

[Deleted account 210609001]

You could try topping up the brake fluid in the ABS unit beneath the tank. I had the same lights (alternate red triangle and "brake failure" flashing), topped it up, and all sorted now.

 

[Bear]

My symptoms were a continuous red triangle and a 4Hz "Brake Failure" flash along with a loss of servo assistance at the rear.. Assuming that I looked in the correct place (my copy of the repROM is not helpful on the subject) the fluid levels were sensible (i.e. the brake fluid in both reservoirs was near to the top).

 

[Readz]

I have just had the same problem, its been in for diagnostic test and came up with a ECU failure. I suggest you get it in to the dealers, mine is in as we speak I’ll let you know how I go on but wont know anything for definite until the end of the week. I did all the checks suggested on here prior to actually taking the bike in but it looks like its going to be expensive and more serious than levels etc.

 

[Bear]

From your location I would guess that you use the same dealer as me, who I'll be phoning tomorrow when they open. I'd be interested to know how you get on.

 

[GSband]

On my 06/2005 R12GS (with servo assisted brakes) the same problem occurred in october 2007. After checking levels etc, I brought bike to dealer. Diagnosis was faulty brake module. Replacement was estimated at 1200€ , but although bike was out of warranty, module was replaced free of charge.

I sold the bike immediately afterwards. A servo system that may not function is a no go for me.

Since 12/2007 happy owner of R12GS with non assisted brakes.

Good luck on whatever troubles you may find !

 

[Bear]

I spent a few minutes yesterday afternoon estimating how much brake fluid to add to compensate for pad wear. The amount is tiny (O-level maths came up with about 8 ml for the rear brake). I added a measured 10ml to each reservoir, which brought the level up a little, then took the bike out this morning. In 35 miles of mixed traffic it worked fine so I'm hoping all I've had is a low fluid warning. Its off to the dealer next week (the earliest they can take me) for a disagnostic check and possible stiff drink before revealing the results.

 

[Readz]

Update.

Just had a call from the BMW dealers, find it hard to believe but great news is, seems its only the battery. They have checked everything out and say the battery doesn’t have enough charge and this is causing the error and also the speedometer not working correctly.

The battery was fine when I put the meter across it but hey. They recon that I have so many things feeding from the battery and also don’t have a BMW battery fitted thus problem.

I have TT spot and fog fitted by a qualified auto electrician, also autocom and TomTom fitted by BM dealer, I think both of these have been wired to the rear socket. The only other item which I fitted to the battery is a heated jacket control which has been disconnected for a few months now.

The after market battery is the Odyssey PC535GS just over 12months old and is connected to the C-Tec charger regularly. I’ll be speaking to the supplier to see if there is any warranty on this.

So that’s the long and short of it, brilliant news if it is only the battery I have no reason to question the dealer. They said they cleared all the faults and took the bike on a long test run with no problems showing. I have now asked if they will sort out the wiring which they think is possibly incorrect, and stick me a BMW battery on. Hope to collect her soon as possible now and will post another update after that.

Hope this helps someone out there and saves them some stress, life’s too short.

 

[Bear]

I suspect the brake servo uses huge amounts of electricity, far more than the alternator can supply on its own. A weak battery could therefore be the cause of the problem. The reason I don't think it is in my case is because it first showed up after about 70 miles riding. If the battery is so sick that it can't feed the servo after 90 minutes charge from the alternator then it would be too sick to supply the starter motor, which I used to restart the engine immediately after the fault light flashed. I'm pinning my hopes on it being a low fluid level. In Readz's case I would suggest that the Odyssey battery is a well-respected replacement for the **** that BMW use and I'd be surprised it it was causing a problem unless an electrical accessory was overloading something. If anyone knows how much current the brake servo takes I'd be intrigued to know.

 

[Readz]

Bear – like you this first time this happened was after a motorway journey to the Midlands from Lancashire around 70-90 miles, just a came off the M-way, the lights started. I continued to run the bike for a couple of weeks after the initial warning and after topping up the levels, checking wires etc but the problem continued until eventually I only needed to cover 20 miles or so before the flashing warnings would appear. The speedometer problem only happened on the way to the dealers, 3 weeks after the initial problem. I see where the dealer is coming from with his suggestions for checking all my extras wiring but I am going to ask him to do a full check on the alternator now as I have my suspicions that could be the problem.

 

[Pukmeister]

Reduced battery capacity - I'd guessed as much (Post #2). The majority of electronic controller faults are caused through voltage transients.

A Hawker Odyssey is warranted for 2 years IIRC providing you use a recommended trickle charger. When I bought my Odyssey the CTEK was the ONLY recommended charger so you should have a warranty.

My Advice:

When stopped at the traffic lights etc, use ONLY THE REAR BRAKE to hold the bike. The servo pressurises the rear brakes then cuts out to save power, cycling on and off periodically as required. The front brake stays on continuously however and drains the battery.

 

[Readz]

Well collected bike on Saturday, got 7 miles down the road and same problem. The dealer assured me they had taken the bike on a long test run and the error was sorted. They recommended that I put a BMW battery on the bike in place of the Oddesy one. I took the advice and purchased a battery and a charger, even had a good chat to the mechanic who convinced me that it was the battery and my TT lights that were causing the problem. So I continued home fitted the new battery and fully charged it with my new BMW charger disconnected everything except my tomtom and autocom which were dealer fitted from new. Went for a ride and again fault popped up at 7 miles down the road, so pissed off with this now, its another hour and half journey back to the dealers now and sorting out a lift back.

My error again is the Red Triangle constant and the break failure flashing once per second. Any ideas?

 

[Pukmeister]

Remove and clean the rear ABS wheel speed sensor/speedo input transducer in the final drive housing.

Use an optimate to ensure the battery really is fully charged.

 

[Bear]

Readz, I suspect your problem and mine are different. I'm back from the dealer this afternoon. Only fault logged was a low voltage error which could have been from when the original battery failed 18 months ago. Dealer opinion is that I've fixed the problem by adding a little fluid to each reservoir. I've had no more flashing red lights in the last 150 miles so I'm hoping he's correct. In your case, given that you mention a speedometer problem (which I didn't have) I suggest following Pukmeister's advice as the rear wheel sensor is used to drive the speedometer and the ABS.

 

[Dellis]

The battery is a BMW item and is 18 months old. The starter motor turns properly so I woulod assume that the battery is in reasonable condition. The connections to it aree clean and tight. I looked at the connectors on top of the fluid reservoirs in case corrosion was causing a problem but both were clean. I doubt if the alternator is faulty because I could restart the engine immediatley after the problem and the tiny battery wouldn't hold hold up the ignition and starter motor for long. Unless someone in south Cheshire has a GS911 and a fondness for beer similar to my own it's a phone call on Tuesday morning.

My battery died at 8 months old the day after a 500 mile run and with no prior warning so you can't discount the battery.........

 

[Lord Vader]

Well collected bike on Saturday, got 7 miles down the road and same problem. The dealer assured me they had taken the bike on a long test run and the error was sorted. They recommended that I put a BMW battery on the bike in place of the Oddesy one. I took the advice and purchased a battery and a charger, even had a good chat to the mechanic who convinced me that it was the battery and my TT lights that were causing the problem. So I continued home fitted the new battery and fully charged it with my new BMW charger disconnected everything except my tomtom and autocom which were dealer fitted from new. Went for a ride and again fault popped up at 7 miles down the road, so pissed off with this now, its another hour and half journey back to the dealers now and sorting out a lift back.

My error again is the Red Triangle constant and the break failure flashing once per second. Any ideas?

Yes unfoortunatly the same happened to me last year and i had the same problem with the dealer not being able to find the fault after having the bike on 4 occasions.
As i pointed out and he would not listen,it turned out to be the final drive.
Might be a idea to have that checked out

http://www.ukgser.com/forums/showthread.php?t=153449

 

[Readz]

Looks like good news for you there Bear. Fingers crossed our friend Mr Pukmeister maybe correct. I took the sensor out late last night and gave it a good clean, it was cacked up with sticky looking oil deposit but also I noticed it was scratched and worn on the surface. Because of the scratches I am going to try to drain the rear housing tonight and stick some fresh oil in.

Way things are at work its probably going to be Saturday before I get all the work done and out for the test run. I just called Motoworks about the part and they have them in stock shop soiled only been tested on a bike at £46.89 which sounds a lot better than a new ecu at £1300.

Thanks for all the replies

 

[Pukmeister]

Readz, are you sure they were scratches and not just fine metallic swarf. The sensor is magnetic so it attracts metallic wear particles from the final drive as the gears wear (bed in) with use. Cleaning off the swarf allows the sensor to work properly again. This could well look just like scratches until you rub it off with a clean cloth.

The sensor is inductive, it counts the raised areas on the rear face of the final drive crownwheel as it passes which creates a square wave output whose frequency is proportional to rear wheel speed. This then tells the speedo and ABS electronics what speed the rear wheel (and hence bike) is doing. If the sensor is disturbed by a build up of swarf particles, it can't produce a square wave output hence erratic speedo and/or ABS operation.

If the sensor truly has scratches on it, there is physical contact between the sensor and the crownwheel, which would suggest the sensor is incorrectly fitted and is sitting too deep in the hole (eg sealing ring missing ??)

Be sure your battery is fully charged too as a low voltage can upset the sensitive electronics in the ABS controller module (Brain).

Keep us updated with the repair, good luck.