Limp mode, reving on idle, and throwing three codes - bad throttle body / DISA?

[pweisansal]

See the issue in action:

Lights:
Brake light
EML
Service Engine Soon

Codes:
P1632 - Throttle Valve adaption not met
P1635 - Throttle Valve Adaptation; Lower Mechanical Stop Not Adapted
P0121 - Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance

This usually comes about as I'm driving. At first, the "brake" light will go on. Shortly after as the speed decreases from not being able to accelerate anymore, the card goes into a lurching motion. I'm not sure if this is technically the limp mode, but I can't accelerate, but it will inch / jump along.

The brake pad light is a bad sensor i need to replace.

I'm thinking it's a bad throttle body or DISA value. Possibly a leak in the throttle elbow.

I have tried to recalibrate the throttle body. Usually I can get the car to run normal for a few minutes if I take the battery off, let it sit, reconnect, and start it up again.

This only happens while driving, not while idling. The video is of the car after I came to stop. I was driving 60 on the thruway, the brake light comes on, car will not allow to be give it gas, forces me to pull into the shoulder, the car limps along until i stop the car and shut it off.

Any ideas?

[328 Power 04]

Nothing to do with DISA, throttle body seems to be bad. Which engine?

[pweisansal]

3.0i

[bmwdirtracer]

Welcome to the forum!

I don't think that's what Abel meant, but, Abel, this is the Z4 '03, judging by the instrument cluster, M54 engine .

I completely agree with Abel, that the Throttle body assembly seems to be the issue.

I would suggest that you remove the intake system before the throttle body. Then, WITH KEY OUT OF IGNITION,, use Carb cleaner and a rag on a stick, to clean the inside of the throttle body, particularly the area swept by the throttle blade. Use as many rags and as much carb cleaner as necessary to ensure the flap moves freely. You will use some gentle tool (finger, etc) to move the throttle blade.

And then use electrical contact cleaner (NO rag, no tools!) to clean the pins and plug which connects the throttle body assembly electrically.

Then, you should clear all codes in all computers, and also clear the adaptations, which will require a good BMW diag system.....which, by the way, Abel can tell you the very best way to set up, for cheap, so that you don't have to keep trying to diagnose this kind of thing with "P-codes", which are highly unreliable.

[pweisansal]

Replaced the throttle body, DISA value, all the boots, and the accelerator pedal - still happening.

BMW dealer can't get me in the clear any codes, adaptations, or diagnose for three weeks. That's their earliest appointment.

[scipiozhp]

Did you ever get this diagnosed? If so, what was the outcome?

[328 Power 04]

The thread is over 5 years old, it may be hard to get a good answer.

If you are having a similar issue, I have found that the cars with the Siemens MS45 ecu had plenty of problems with the ECU's throttle control. Often, it requires an ECU change. It's not terribly hard to get it done, but it's not a simple DIY you can do at home to program another ECU in.

- - - Updated - - -

In fact, I think that I have seen an equal amount of throttles to ECUs being replaced.