Fault codes: DME Electric Throttle Self-test (6B) and DME Driver / fuelpump relay (1)

[ATB88]

Was poking around with my Schwaben scanner today and read fault codes. To my surprise, I found two:

6B: DME Electric Throttle: Self-test
1: DME Driver / fuel-pump relay

Surprising because I had just scanned for fault-codes a few days ago in Torque and there was nothing there, and my car has very rarely had any codes over the 30k miles I've owned it.

I erased them and went for a long drive, checked again and they didn't come back. I do worry, however, that it could be true that the problems that caused these codes took a long time to build up enough events to trigger fault codes, and maybe if there still is a problem I won't know because the codes won't come back for a while.

Obviously, 1 points to the fuel-pump relay being bad. This would be great if true because it could be the solution to my intermittent warm hard start issue (see https://nam3forum.com/forums/forum/m...rd-warm-starts). Is there way I can test the relay to know for sure if it's having problems? New one's $145, so it would be nice to know before throwing cash at it.

How about "6B: DME Electric Throttle: Self-test", anyone have experience with this one? I google searched and found stories in other forums of people dealing with this code, but it was always accompanied by other codes pointing at TPS sensors being bad which I don't have. Both TPS in the engine bay are new-ish (<10k miles), but the throttle pedal is original.

One thing to note is that I pulled the fuel rail and put in new injectors a few weeks ago. This involved pulling the fuel pump fuse (54 in the fusebox above the glovebox) and cranking the car to relieve fuel pressure. Could that have caused the fuel-pump relay code and/or the throttle self-test code? I'm pretty sure I checked for codes and cleared them after that whole injector job, but maybe I messed up.

I would actually be kind of excited if these codes were legit (weren't caused by cranking without fuse 54 as described above) and pointed to some underlying problems. I've been chasing down intermittent hard start and high fuel trim issues for a while, but have had no success in figuring out their cause. These codes may help.

Anyway, any information from times anyone has had/dealt with these codes would be appreciated!

[repoman89]

I had 6B on my M5 after I forced the throttles open for cleaning the other day .. cleared and never came back. Might have had it on my M3 after doing the same but I can’t remember for sure. Any chance you disturbed the actuator for one reason or another?

[ATB88]

I had 6B on my M5 after I forced the throttles open for cleaning the other day .. cleared and never came back. Might have had it on my M3 after doing the same but I can’t remember for sure. Any chance you disturbed the actuator for one reason or another?

Thanks! Wouldn't be shocked if I'd pushed on the actuator arm at some point, as I pulled the air and fuel rails a couple weeks ago. Again I'm pretty sure I looked for and cleared codes after that job, but, I do make mistakes so maybe I'm remembering wrong. Good info, though, it might be nothing. Then again, I have messed with the actuator arm many other times and a code never popped up (for example jamming the ITBs open with a roll of tape to do a compression test).

Interested in hearing if there's someone who has had it and it wasn't nothing, though!

[ATB88]

Huh, more googling has gotten me confused. Some people describe the fuel pump relay as being behind the glovebox, and some have described it as being in the back of the car near the fuel pump. Also, I've found two different parts that claim to be E46 M3 fuel pump relays that look very different (and differ greatly in cost): https://www.fcpeuro.com/products/bmw...m3-61357892976 and https://www.ecstuning.com/b-bosch-pa...xoCWckQAvD_BwE

Where's the fuel pump relay in a US spec vert, and are there two?

[terra]

The black one is the correct relay for us spec cars.

it’s located behind the passenger rear “door” panel for convertibles

[ATB88]

The black one is the correct relay for us spec cars.

it’s located behind the passenger rear “door” panel for convertibles

Dang, it's the expensive one. Thanks, terra! I'll pickup a continuity tester and some leads tomorrow, see if I can test it before buying a new one.

[Cubieman]

Was poking around with my Schwaben scanner today and read fault codes. To my surprise, I found two:

6B: DME Electric Throttle: Self-test
1: DME Driver / fuel-pump relay

Surprising because I had just scanned for fault-codes a few days ago in Torque and there was nothing there, and my car has very rarely had any codes over the 30k miles I've owned it.

I erased them and went for a long drive, checked again and they didn't come back. I do worry, however, that it could be true that the problems that caused these codes took a long time to build up enough events to trigger fault codes, and maybe if there still is a problem I won't know because the codes won't come back for a while.

Obviously, 1 points to the fuel-pump relay being bad. This would be great if true because it could be the solution to my intermittent warm hard start issue (see https://nam3forum.com/forums/forum/m...rd-warm-starts). Is there way I can test the relay to know for sure if it's having problems? New one's $145, so it would be nice to know before throwing cash at it.

How about "6B: DME Electric Throttle: Self-test", anyone have experience with this one? I google searched and found stories in other forums of people dealing with this code, but it was always accompanied by other codes pointing at TPS sensors being bad which I don't have. Both TPS in the engine bay are new-ish (<10k miles), but the throttle pedal is original.

One thing to note is that I pulled the fuel rail and put in new injectors a few weeks ago. This involved pulling the fuel pump fuse (54 in the fusebox above the glovebox) and cranking the car to relieve fuel pressure. Could that have caused the fuel-pump relay code and/or the throttle self-test code? I'm pretty sure I checked for codes and cleared them after that whole injector job, but maybe I messed up.

I would actually be kind of excited if these codes were legit (weren't caused by cranking without fuse 54 as described above) and pointed to some underlying problems. I've been chasing down intermittent hard start and high fuel trim issues for a while, but have had no success in figuring out their cause. These codes may help.

Anyway, any information from times anyone has had/dealt with these codes would be appreciated!

You told me you had pulled your fuel rail multiple times recently. I had the same code (1) after pulling mine. Its produced when you pull the fuel pump relay fuse and let the car start and die.

[ATB88]

You told me you had pulled your fuel rail multiple times recently. I had the same code (1) after pulling mine. Its produced when you pull the fuel pump relay fuse and let the car start and die.

Rats. This may well be a red herring then. Again I'm pretty sure I pulled and cleared codes after that job, but maybe the Schwaben tool can read/clear codes that for some reason Torque can't? ¯\_(ツ)_/¯

I'm not gonna go out and buy a relay unless I'm sure, but might as well test my current one as I'm pulling my backseats for some much needed cleaning anyway.

[Cubieman]

Rats. This may well be a red herring then. Again I'm pretty sure I pulled and cleared codes after that job, but maybe the Schwaben tool can read/clear codes that for some reason Torque can't? ¯\_(ツ)_/¯

I'm not gonna go out and buy a relay unless I'm sure, but might as well test my current one as I'm pulling my backseats for some much needed cleaning anyway.

I've got torque and I use it on my 2000 WJ jeep, I personally wouldn't "trust" it for the bimmer but for all I know it will pull/clear all the same codes as the Schawben tool. Why don't you use Martyn's new free DME Ultility? Thats easy peasy and free (thanks Martyn!!).

[ATB88]

I've got torque and I use it on my 2000 WJ jeep, I personally wouldn't "trust" it for the bimmer but for all I know it will pull/clear all the same codes as the Schawben tool. Why don't you use Martyn's new free DME Ultility? Thats easy peasy and free (thanks Martyn!!).

Yeah, I haven't gotten around to installing it on my BMW laptop yet, but looks nice and dependable. Schwaben tool's handy because you can just keep it in your driver door storage compartment and whip it out whenever. Torque's even more handy because I can just use it on my Avant 4 nav screen without even having to plug anything in.

I've got the relay out, and I watched some youtube videos on how to test a fuel pump relay. Those videos seem to assume the relay has 4 or 5 pins, but this one has 8. So, I'm not sure what to do.

Found a circuit diagram for the relay, but I haven't looked at one of these since college. Would anyone be able to tell me which pins I want to connect to 12V and which ones I want to check continuity on? Interestingly, when connected to the car, the relay doesn't "click" when I turn on the ignition. The relay next to it (for heated rear window) does, but the fuel pump relay does not. Car starts regardless, though. But maybe this relay isn't supposed to make an audible click? idk man.

To be clear, the reason I want to believe/verify that there's a problem with the fuel pump relay is that I'm having intermittent hard starts and everything else in the fuel and air intake systems is brand new, except this relay.

[ATB88]

Okay I got a 12V battery and DMM for testing. Can successfully test for continuity in a normal 5 pin relay (like the yellow and green ones used in various places in the car). Also they obviously click open under 12V, even before testing continuity.

I know that the fuel pump relay shouldn't audibly click open/closed because it's FET based, so the only thing I can do is test for continuity when energized. But I'm not sure which pins are which here. If only pins 2, 4, 5, 6, and 8 were present, it would look exactly like the 5 pin relay, down to positioning and orientation of pins. This made me hope that these pins serve the same purpose as those in the 5 pin relay so I tried to test the same way -- no continuity.

Looking at the circuit diagram and the numbering of the terminals on the diagram, it doesn't seem like my guess is right, though. But the circuit diagram only tells you what pins 1, 2, 5, 7, and 8 are. And it doesn't look like pins 7/8 have anything to do with the other part of the circuit? If anyone can tell me whether it's possible for me to test this relay I'd appreciate it :]

[Pnick]

See if this diagram can help...

[ac427]

I believe there is both a light green relay to switch the 12 volts and the black PWM module to control fuel pressure.

The pump in the E46 M3 has is output pressure controlled by a signal from the EKPM aka fuel pump control module aka the black relay.

[ATB88]

I believe there is both a light green relay to switch the 12 volts and the black PWM module to control fuel pressure.

The pump in the E46 M3 has is output pressure controlled by a signal from the EKPM aka fuel pump control module aka the black relay.

Is this true? I had read that on our cars that light green relay next to the black one is actually used for powering the heated rear windshield defroster, and that the fuel pump is completely controlled by the black relay.

[terra]

Is this true? I had read that on our cars that light green relay next to the black one is actually used for powering the heated rear windshield defroster, and that the fuel pump is completely controlled by the black relay.

You’re correct.