Chevy & GMC Vans

Hi all,
I wonder if you guys could give me a hint how to solve my problem:

I have a 1995 Astrovan with a W-engine and 40L60E trans.
When I am driving down the road and I just slightly touch the brake pedal, the ABS pump starts working, making this brrrrrr-sound. This does not happen all the time, but once in a while.
Sometimes, when I am driving on the highway at 55 miles, the needle of my speedometer is starting to tremble and shortly after that the autotrans is loosing the gear or fails to shift.
OBD-I gives me troublecode 37.
So far I have replaced the front wheel ABS sensors and the Vehicle Speed Sensor.

Do you you have any idea, what could be the reason for this malfunction?

Thank you and kind regards
Martin

yes, ME TOO! Anyone have any ideas?

Torque Converter Clutch Brake Switch Circuit Error

The ECM monitors the Torque Converter Clutch Brake switch to determine if the brakes are applied or not. It uses this signal to help determine if the the Torque Converter Clutch should be applied.
Fault Code Description
37 - Torque Converter Clutch Brake switch circuit error
Symptoms
Torque Converter Clutch Brake switch will not come on or operates erratically
Common Problems
Faulty or out of adjustment Torque Converter Clutch brake switch

Maybe something related to your EBCM module which is on your frame under drivers seat more or less,I am no expert though, just something to look into if other paths lead to a dead end.

Is that what you are talking about Capt'n, maybe I missed it, that's a bit over my head.

I’d start by looking at the two switches under your brake pedal. One is for the brake light and the other is for torque converter lock up

http://www.astrosafari.com/viewtopic.php?p=52804