Throttle Stuck

[harleyclassic2]

I have P1639 & P1636 DTC'c which are Throttle Stuck Permanently & Throttle Valve Control Circuit. (No gas, sputtering no acceleration etc)

Was wondering if a low battery/bad alternator or regulator cold cause that ?? Since its an electronic throttle. Every time I had a gizmo left plugged in the cig lighter for a little while -- batt down below 12.6V --and had all the typical symptoms like shaking, not moving/accleration etc)

Anyone ? Thanks.

[Zulu95]

It could also be the throttle pedal. I had to change the one in our X5 out some years ago.

[harleyclassic2]

You mean the PWG - potentiometer above the gas pedal -- that translates physical pedal movement to the DME - engine management --- OR the physical foot pedal ?

(My batt is not holding a charge - gets down to 11.7 after 1 mt of lights - which is complete discharge but alternator seems OK-- so guess I will get one)

[Zulu95]

I did the whole assembly at the time.
Have3 you had the charging system/battery checked at Autozone or the like? I would also be sure to unplug the gizmo as it takes very little to prevent the sleep mode so all the electronics continues to draw power. It is this drain that draws down the battery.

[harleyclassic2]

I had removed 3 yr old battery and had it checked at autozone --was OK then - but had just filled with distilled water so might have helped. But now with volt meter its low 12.1 (50%) & when engine running it is 13.9 (should be between 13.5 to 14.5) so charging system seems to work but batt not holding. I might as well buy a new indy battery.

When you replaced acclerator assmbly did you have DTC ? what prompted replacement.

[Zulu95]

Had a throttle pedal error message. It was a long time ago so I do not remember the exact code. I use a Peake Scan Tool and throttle was first on the list for cause. I had my mechanic replace the assembly and the code did not return after reset nor since. (About 5 years or so.)
BMW tend to charge to a max voltage of around 13.85V. There was a mod published in the club mag some time ago to boost this to 14+v by inserting a diode in the ground circuit of the alternator sense circuit as the 13.85V is generally around the bottom of healthy charging voltages.
I had an Exide battery fitted shortly after I bought the beast. It was the third battery (at least) that had been fitted. I know this because the problem battery removed was a VW type that was too small for the vehicle requirements. So much for the CPO pre-delivery inspection!
Now, almost 8 years later the Exide is still there but I do expect to have to change it out sometime in the next few years.