Engine Malfunction - Code 27E3

[yeah_knee]

That brake booster sensor code (27E3) won't stop popping up. Car will go into limp mode once a month because of it . I usually restart my car and it goes away.

I've replaced the sensor twice within 4 months believe it or not, and it still continues to come back. The fluid isn't overfilled and hasn't dripped onto the sensor (which I know is the common reason those sensors go bad). My local shop EAS (Anaheim CA) tried updating my ABS software to see if that would help. Code still popped up yesterday. We're kind of stumped at this point. Any help or insight would help.

[dpaul]

Originally Posted by yeah_knee

That brake booster sensor code (27E3) won't stop popping up. Car will go into limp mode once a month because of it . I usually restart my car and it goes away.

I've replaced the sensor twice within 4 months believe it or not, and it still continues to come back. The fluid isn't overfilled and hasn't dripped onto the sensor (which I know is the common reason those sensors go bad). My local shop EAS (Anaheim CA) tried updating my ABS software to see if that would help. Code still popped up yesterday. We're kind of stumped at this point. Any help or insight would help.

Replaced the sensor twice?? Was that the advice from EAS?

Vacuum sensor, brake booster, plausibility

Sensor value deviates substantially from model value, with sensor value > Model value ensuring that ELUP activation threshold remains valid

Service Notes
1. Check plug and wire to differential pressure sensor,
2. Replace differential pressure sensor
3. Check vacuum line,
4. Check 1-way check valves,
5. Check brake booster

[Helmsman]

Brake booster making a lot of buzz as if the sensor would be broken?

[yeah_knee]

Originally Posted by Helmsman

Brake booster making a lot of buzz as if the sensor would be broken?

No everything operating and working fine

[Helmsman]

Originally Posted by yeah_knee

No everything operating and working fine

If the sensor broke (from fluid overspill etc) it won't tell the pump to stop hence it will continue to work, you def will hear this buzz from the front/left side. Plenty good threads on the board about this for more details.

No personal experience from the actual pump but from what I read fairly easy to access (behind fender liner) and replace if needed. Not sure if a pump issue could generate this code though.

[yeah_knee]

Originally Posted by Helmsman

If the sensor broke (from fluid overspill etc) it won't tell the pump to stop hence it will continue to work, you def will hear this buzz from the front/left side. Plenty good threads on the board about this for more details.

No personal experience from the actual pump but from what I read fairly easy to access (behind fender liner) and replace if needed. Not sure if a pump issue could generate this code though.

The thing is the sensor is brand new. Doesn't appear fluid has spilled on it. And I still keep getting the engine code. The pump has been tested as well and works fine.

[yeah_knee]

Originally Posted by dpaul

Replaced the sensor twice?? Was that the advice from EAS?

Vacuum sensor, brake booster, plausibility

Sensor value deviates substantially from model value, with sensor value > Model value ensuring that ELUP activation threshold remains valid

Service Notes
1. Check plug and wire to differential pressure sensor,
2. Replace differential pressure sensor
3. Check vacuum line,
4. Check 1-way check valves,
5. Check brake booster

They warrantied the first sensor and put in the second one for free

[yeah_knee]

Ended up replacing brake booster. Let's see what happens

[Helmsman]

Originally Posted by yeah_knee

Ended up replacing brake booster. Let's see what happens

Interesting, pls report back mate.

[yeah_knee]

Originally Posted by Helmsman

Interesting, pls report back mate.

Same code came back... but different description this time. Anyone seen this before?

[yeah_knee]

Originally Posted by yeah_knee

They warrantied the first sensor and put in the second one for free

We've literally done everything on this list. I changed the brake booster a month ago as well. and the engine malfunction came back a few days ago

[Ajolives]

Kinda arm chairing this , but I would think tracing wires would be the next step - may have a break, loose connection, etc. Or did they do some sort of resistance test as part of step 1. Possible the tech missed something - double check all work.

[Adriano917]

I had the exact same issue but mine ended up being the Brake Booster, have you checked all the vacuum lines properly ? Use brake cleaner and see if the idle goes up.

[yeah_knee]

Originally Posted by Adriano917

I had the exact same issue but mine ended up being the Brake Booster, have you checked all the vacuum lines properly ? Use brake cleaner and see if the idle goes up.

According to my shop. They have. I'll probably bring it back in to them next week to go through a check again

[yeah_knee]

Originally Posted by Adriano917

I had the exact same issue but mine ended up being the Brake Booster, have you checked all the vacuum lines properly ? Use brake cleaner and see if the idle goes up.

I've literally done everything.. even changed the booster

[Scooterfreeride62]

2008 E92 M3 I have the same code happened twice while stopped at a stoplight with foot on brake. Engine RPM jump up was close to 1000. Secondary code first was 2796 then the second time was 2B57.

Did anybody figure out what might cause this? When I step on the brakes once then release. I do hear a buzzing sound for 5 seconds or so and then stops.