"Fault in the engine control" warning on R18B [SOLVED]

[BeemeR18]

@Ulrich exhaust servos no longer there but using the Healtech ESE in place, this hasn't caused issues so far.

@jp R18T that's right I read about the coils on another BMW forum and had a pair of upper & lower coils (so one cylinder set) from another R18:
One by one I replaced each of the 4 original coils resetting the code each time but every time the code came back - unless 2 coils failed one on each side?! or it takes longer for the code to clear with the replacement coils? I don't know


Using another OBD app I'm still getting the codes below:

 

[Mac]

Just a thought but have you tried swapping the Healtech’s around. I think you have to use two on these bikes I am wondering if one has failed or has a bad connection giving an incorrect reading back to the control unit.

 

[Star-Lord]

Just a thought but have you tried swapping the Healtech’s around. I think you have to use two on these bikes I am wondering if one has failed or has a bad connection giving an incorrect reading back to the control unit.

Good idea...

Even if the error triggers after rolling the Healtech modules.. check with the OBD tool and see if the code changes, maybe indicating the failed Healtech module moved to the other exhaust side.

 

[Ulrich]

Just a thought but have you tried swapping the Healtech’s around. I think you have to use two on these bikes I am wondering if one has failed or has a bad connection giving an incorrect reading back to the control unit.

Yup ... or that one!

 

[BeemeR18]

Regarding the ESE: I disconnected them completely, cleared the codes, no change.

I started taking apart the top of the engine (air filter area), checked the camshaft sensor and the fuel‑pump connector. Cleaned both, reconnected, still no difference. When I cleared the codes earlier, I copied one into ChatGPT along with the list of things I’d already checked:

• Battery terminals
• Fuses
• Crank/camshaft sensors
• Coils etc.

ChatGPT suggested fuel pump or throttle body (because of ride‑by‑wire). I thought that was odd, I expected lambda sensors - but whatever. At that point I was ready to give up and book it into the local Motorrad dealer.

I put most of the bits back together, started the bike, and the error appeared. Turned it off, tapped the side of the tank, turned it on again… and this time no error. The warning light on the side stayed on, but the dash showed Check – OK in green?


Still didn’t trust it, so I went to the dealer, their earliest slot is in July and I booked it. When I got home, I paid more attention to the fuel pump:

• Turn on - no pump noise, error appears
• Turn off
• Tap tank (slap?) - turn on - pump makes a noticeably different noise for 2 seconds, no error

So now I’m wondering how likely is it that the fuel pump has actually failed (and at only ~6k miles)?

 

[Star-Lord]

Isn't the fuel pump inside the tank? Might be worth draining the tank and going after the pump assembly.. Banging on the tank, are you thinking something is intermittent..?

You'll have this figured out before your service appointment date...

I thought the problem was that your bike was set in ROLL mode, vs ROCK mode... LOL

 

[Mac]

The fuel pump is cooled by the fuel in the tank, if the previous owner had a habit of draining well into reserve on a regular basis then it is quite possible to damage the pump. Sounds like you are onto something especially remembering your first post about the low state of fuel and the fault showing then. Keep going, you will get this.

 

[Star-Lord]

@BeemeR18 - hopefully this helps..

 

[Star-Lord]

 

[Ulrich]

Could it be simply some issue with the electrical plug connection that one has to unplug to remove the tank? ... a bad connection there could throw a fault ... and you tapped on the tank and that seem to fix it ... do you know if the tank was removed before? I had mine off a couple of times and the fuel and electrical connection are a bit of a pain in the @$$ to dis-and-reconnect ... just thinking out loud

 

[Star-Lord]

Since you have your fuel tank removed; now is a good time, to upgrade the brittle plastic fitting with a stainless steel piece:

See the following forum thread with additional fuel pump diagrams:

Post in thread 'Low Fuel Warning Will Not Reset'

Sep 29, 2025

Any chance you damaged something when you lifted the tank? There is a plastic captive connector; which technically speaking, normally gets disconnected prior to lifting the tank, so as not to stress the plastic fitting on the fuel tank.

Folks have cracked the fuel line fitting under the tank and swapped out the plastic fitting, with a stainless steel adapter..

I'm not sure what sensor is used to determine the fuel level; definitely, keep us posted as to what you find...

• Star-Lord

• 

 

[Star-Lord]

 

[BeemeR18]

Cheers @Star-Lord diagrams are helpful

@Ulrich I agree the connector under the tank is a bit of a pain, very fiddly but I'm aware of it, had it disconnected and cleaned before

Now I took a bit of a step back, was nearly convinced it was the fuel pump after the experiment I shared - so on Thursday I ordered a used pump from another R18, lower mileage than mine.

I thought before emptying the tank I'd just connect the other pump+fuel level sensor to the bike to see if anything changes:

Old pump connected - Turn on - error
Cleared codes - Turn off
Swap pumps via connector under the tank
'New pump' - Turn on - same error....

So, back to square one. The other thing ChatGPT suggested was the Throttle body

Any thoughts on troubleshooting that? Or should I leave it to the dealer

 

[fleabag]

Since you have your fuel tank removed; now is a good time, to upgrade the brittle plastic fitting with a stainless steel piece:

See the following forum thread with additional fuel pump diagrams:

Post in thread 'Low Fuel Warning Will Not Reset'

Sep 29, 2025

Any chance you damaged something when you lifted the tank? There is a plastic captive connector; which technically speaking, normally gets disconnected prior to lifting the tank, so as not to stress the plastic fitting on the fuel tank.

Folks have cracked the fuel line fitting under the tank and swapped out the plastic fitting, with a stainless steel adapter..

I'm not sure what sensor is used to determine the fuel level; definitely, keep us posted as to what you find...

• Star-Lord

• 

View attachment 21793

I’m surprised BMW is still using plastic for these connectors. You would have thought they learned their lesson with all the other bikes where these have snapped.

 

[Ulrich]

Wow ... you are really at a tough spot ... now, thinking back ... you were able to make the fault go away at one point by tapping the fuel tank ... and sometime in an earlier post you mentioned "DME: Fuse active: Component group 1, overload current" have you inspected the wiring harness from the fuel pump to where it goes down the frame and checked if it is pinched or rubbed through? especially around the part on top of the motor where you can take the 2 halves off to get to the air filter. You did say that happened after you received the bike ... used ... maybe the dealer checked the filter and in the process pinched a wire? ... sorry clutching at straws here ... the bike seems to be running fine ... so IMO it is nothing major like a throttle body or such, I think you would seriously notice that in performance ... but like I said I am clutching at straws here

 

[Star-Lord]

Wow ... you are really at a tough spot ... now, thinking back ... you were able to make the fault go away at one point by tapping the fuel tank ... and sometime in an earlier post you mentioned "DME: Fuse active: Component group 1, overload current" have you inspected the wiring harness from the fuel pump to where it goes down the frame and checked if it is pinched or rubbed through? especially around the part on top of the motor where you can take the 2 halves off to get to the air filter. You did say that happened after you received the bike ... used ... maybe the dealer checked the filter and in the process pinched a wire? ... sorry clutching at straws here ... the bike seems to be running fine ... so IMO it is nothing major like a throttle body or such, I think you would seriously notice that in performance ... but like I said I am clutching at straws here

To add to @Ulrich thoughts; I do recall that early on within the forum discussions, Model B and TC owners had reported cracked wires within the wire-harness, up near the steering tube on both sides. Again, since it looks like you have the fuel tank removed; this is a good opportunity to closely inspect the wiring for EVERYTHING .. I can try and post wire-harness diagrams if you think that will help, they sometimes highlighted in blue color.

I would even look for rodent chewing damage, hair stuck to sticky tape, nest or material used to make a nest evidence..

 

[BeemeR18]

Cheers guys, I've had a look tracing the wiring but honestly couldn't see anything wrong - but again not taken apart the harness to check each wire inside. Will have another closer look tomorrow.

PS. Is there any active/electrical component in the fuel evap system?

 

[BeemeR18]

Got a call from my father, who’s got decent experience with cars and bikes. I told him about the issue and everything I’ve done so far.

Long story short, he had a go at me for riding on fuel reserve (that was the previous owner tho). His point was similar to @Mac re immersed pumps, they’re cooled by fuel, and regularly running low can shorten their lifespan.

His theory is:

• Pump no longer within params - the bike’s pump is going and no longer producing the required pressure for the injectors
• The pressure is still “OK,” just below the lower threshold (~3–3.5 bar?), which is why the bike still runs
• The fuel pressure sensor (I believe on top of the engine, right side) is what’s triggering the error because the pump isn’t generating enough pressure

So, according to him, me connecting another pump electrically under the tank tells us nothing. Since I didn’t connect it to the fuel lines, it never produced pressure in the circuit, meaning the fuel‑pressure sensor would still throw the same error.

Could make sense. Which brings me back to the fuel pump being the main culprit.

 

[Ulrich]

.... wow ... I sure hope so ... this one is a tricky one!

 

[Star-Lord]

Got a call from my father, who’s got decent experience with cars and bikes. I told him about the issue and everything I’ve done so far.

Long story short, he had a go at me for riding on fuel reserve (that was the previous owner tho). His point was similar to @Mac re immersed pumps, they’re cooled by fuel, and regularly running low can shorten their lifespan.

His theory is:

• Pump no longer within params - the bike’s pump is going and no longer producing the required pressure for the injectors
• The pressure is still “OK,” just below the lower threshold (~3–3.5 bar?), which is why the bike still runs
• The fuel pressure sensor (I believe on top of the engine, right side) is what’s triggering the error because the pump isn’t generating enough pressure

So, according to him, me connecting another pump electrically under the tank tells us nothing. Since I didn’t connect it to the fuel lines, it never produced pressure in the circuit, meaning the fuel‑pressure sensor would still throw the same error.

Could make sense. Which brings me back to the fuel pump being the main culprit.

Any luck with the new fuel pump, fully installed within the entire system?