Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Bike of the Month Challenge!
1 - 20 of 29 Posts

·
Registered
Joined
·
41 Posts
Discussion Starter · #1 ·
On my 400 mile trip yesterday the MIL came on and threw a P1576 code.. can't find any Triumph related info on it..
Any insight would be appreciated on how to rectify this problem.

Sent from my SM-G920V using Tapatalk
 

·
Premium Member
Joined
·
20,740 Posts
I think it might be something to do with a bad brake light switch. Do both front and rear brake light switches work?

It seems odd that the ECU is monitoring the working of the brake lights but it does because they're a vital part of the optional cruise control which is disabled momentarily by applying the brakes.
 

·
Registered
Joined
·
72 Posts
I think it might be something to do with a bad brake light switch. Do both front and rear brake light switches work?

It seems odd that the ECU is monitoring the working of the brake lights but it does because they're a vital part of the optional cruise control which is disabled momentarily by applying the brakes.
There's no cruise control option on the Street Twin.
 

·
Premium Member
Joined
·
20,740 Posts
Right, but the chances are that it shares some hard and software, wiring looms, etc with the models that have the option. Triumph might have left the facility to monitor the brake lights only.

Are they both working?

That code is also used for throttle position sensor, also associated with cruise control. Not the usual cable throttle sensor that sits on the butterfly valve, but the actual twistgrip position.

Did you use a code reader to determine that code? they have a function to turn the light off and delete the code, do that and see if it comes back.

Most readers also have the facility to monitor the throttle opening percentage, often labelled "TP" or "TPS". Operate the twistgrip and see that it increases and decreases smoothly without breaks. See that it settles at 0% with throttle fully closed.
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #5 ·
I used a bluetooth code reader.. I'll check the TPS you spoke of tomorrow.. I have changed the brake light out to an LED strip but it works perfectly as far as run/brake with either front or rear.. only other difference from stock is that I'm not currently running a tag light.. could that be throwing it?
I have cleared the code and it eventually comes back on.

Sent from my SM-G920V using Tapatalk
 

·
Premium Member
Joined
·
20,740 Posts
I used a bluetooth code reader.. I'll check the TPS you spoke of tomorrow.. I have changed the brake light out to an LED strip but it works perfectly as far as run/brake with either front or rear.. only other difference from stock is that I'm not currently running a tag light.. could that be throwing it?
I have cleared the code and it eventually comes back on.
Good to know a Bluetooth reader works fine. Some folk are worried the new bikes have a sacrosanct ECU that won't allow home OBDII diagnostics.

Did the code come up immediately or soon after the LED rear light was fitted? The ECU could monitor the brake light by current flow rather than voltage and the much-reduced current used by LEDs could cause it to believe the brake light is not working.
 

·
Registered
Joined
·
2,352 Posts
When I did a quick interweb search for generic ob2 codes,most were related to brakes and voltage or position sensor. I think Forchetto is steering you in the right direction. I don't have my manual handy to check that code for triumphs.
Did you use a resistor or relay for the led?

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #8 ·
It did start after the new light was fitted, but these bikes come with an LED tail from the factory.. I just assumed it couldn't have been that much less draw.. I'll going to have to play with it to figure it out I guess..

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #10 ·
No, I haven't had much time to fiddle with it but I had reset the code with my reader and it hasn't come back on yet.. I'm sure it'll come back after a few more miles have been ridden though

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #12 ·
Part of me thinks it because I'm not currently running a tag light.. was going to get the plate bolts with leds built in but I'm curious if the code is caused by the lack of a bulb..

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #13 ·
Ok so, not sure what the issue turned out to be.. I ended up clearing the code to see if it would come back and it hasnt.. it's been a couple hundred miles so maybe (hopefully) it was a fluke.

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
6 Posts
I have recently received this code also after installing my R&G fender eliminator kit on my thruxton R. I spoke with R&G and they are aware of this error code arising after installation of their kits and have offered to send me a new version of their brake light unit which has a few extra diodes from what I was informed. The dealer has suggested to install the original unit just to clarify that it isn't the actual brake switch that is faulty.
 

·
Premium Member
Joined
·
1,521 Posts
I have recently received this code also after installing my R&G fender eliminator kit on my thruxton R. I spoke with R&G and they are aware of this error code arising after installation of their kits and have offered to send me a new version of their brake light unit which has a few extra diodes from what I was informed. The dealer has suggested to install the original unit just to clarify that it isn't the actual brake switch that is faulty.
Is not related to the brake light in any way.
The switches for the brakes are spdt, meaning single pole dual throw. When neither are pulled the ECU gets a signal on one pin, and with either or both pulled the signal goes to the other pin.
If the ECU detects neither on, or both on simultaneously it reported that error.
So you need to check the brake switches and the connections leading back to the ECU.
I have the same issue, and I hope to get around to testing it all out next week.

Sent from my SM-N920S using Tapatalk
 

·
Premium Member
Joined
·
1,521 Posts
Update and fix...
So I called R&G, and they said they had issues with their tail-lights regarding "problem with a diode", and they sent me a replacement which I fitted it last night.
No error so far, and my bike now changes modes while I'm moving, so my guess is that once there's a P1576 error generated it prevents the 'mode change while moving' function.

From what I could see (and I tested it) all they've done is fit a diode in series on the red wire.
I believe this is to prevent feedback voltage present from the rear light (as opposed to brake light) onto A07 of the ECU, which would trigger the "there should not be a signal on both A07 and A06" error.
The inline diode simply isolates it, so if you get the same error simply add something like a 1N4001 diode in series with your brake-light wire (green-purple) and the problem should go away :)
 
  • Like
Reactions: Delta and Forchetto

·
Registered
Joined
·
2 Posts
I have a similar situation. Had the 500-mile inspection at the Triumph dealer last week for my 2017 Bonneville T100. The next couple of commuting days I didn't have any issues. However today I went for a ride at highway speeds and about 40 miles into the ride I got the engine light (MIL) indication. I cut my ride short and headed back to the home garage. I connected to the OBDII interface on the bike and see a P1576 ECU error code. I cleared it but suspect it may come back. While the MIL indication was on, engine was running a little rough. After I cleared the error code, it seems to be running in its normal smooth self.
-Bob Morales.
 

·
Premium Member
Joined
·
1,521 Posts
P1576 won't have any link to the engine running rough, as it's simply a brake switch detector warning. If it keeps popping up then there may be an issue with the rear brake lamp unit, in which case I'd suggest you see if you can get it replaced under warranty before your two years are up :)
 

·
Registered
Joined
·
197 Posts
So I am helping a buddy who appears to have the same type of error (Brake 2 switch correlation error with brake switch 1). According to another thread Surendra posted that code is P1577.

My buddy has the British Customs fender eliminator not the R&G. I don't know how the wiring is on the R&G, but on the BC they only use 5 out of the 6 stock wires. I presume that is because the bulb for the running light also acts as the bulb for the plate illumination.

Reading the above I presume the red wire on the R&G mates to the stock green/purple. I have no issues installing a diode, but I don't want to cut into the stock wiring. I figured I would splice in the diode on the fender eliminator side of the connector. Since I get the opposite code I am not sure which wire to splice the diode to and which direction. Black or green/purple or one of the others.
 

·
Premium Member
Joined
·
1,521 Posts
P1577 is "Brake 2 switch correlation error with brake switch 1" whereas P1576 is "Brake 1 switch correlation error with brake switch 2"
My guess is that if the rear brake switch is faulty we get no signal on A06 when the brakes are off, but signal on A07 when front brake is on, and I'm guessing it reports this as a brake 2 failure (P1577).
I believe P1576 is thrown if there is a voltage always present on A07 when the brakes are off (which should be low), so one error is for A07+, A06+, and the other for A07-, A06-, both of which are invalid combinations (should only ever be either A07+, A06- or A07-, A06+).
Hopefully that makes sense.
So my suggestion is that in his case there is a disconnect either on the Black (B) between the rear brake switch and the ECU, or between the green-blue wires between the two switches.

Easiest test (if you have a multimeter) is to remove the plug from the ECU, and test for continuity between the Yellow wire on the front brake switch, and the pins 6 and 7 in the end of the ECU connector. Pin 6 should normally be conducting (low resistance, e.g. less than about 10Ω), and using either brake should open that circuit.
Pin7 should normally be open circuit, but closed when either brake is activated.
If you don't get that, then you should test the links between A06 and A07 and the rear brake switch.

I don't think your issue is diode related, as that would cause P1576, although I could be wrong.

A word of warning. Do NOT stick the end of a multimeter probe into an ECU connector!!! The sockets in the plugs are small, and sticking a large meter probe in them makes them a loose connection, so they don't connect properly after they are reconnected. Stick a pin into the end of the connector, and test onto that.
We've had two bikes in the last two weeks with stretched ECU sockets where other garages have done this trying to diagnose problems, and we have to remove every connector and bend it closed :/
 

Attachments

  • Like
Reactions: Delta and Forchetto
1 - 20 of 29 Posts
Top