My 2000 Bonneville SSEi stalls when driving and gives no trouble codes. It happens at any speed, but mostly on the highway. It also momentarily (about 1 second) cuts out on the highway. When it temporarily cuts out, the battery light comes on but all the accessories and power steering seem to work ok. It usually starts back up right away, but not always.

In the past I fixed the stalling problem with a new crank sensor and a MAF sensor from the junkyard, which fixed the problem till now. I recently replaced the MAF with a brand new sensor, which has NOT fixed the problem. Fuel pressure at the rails was perfect last time I checked it.

I don't think it'* a fuel problem and I'm leaning toward an ICM, ECM, TPS or possible ground problem. I also had a 99 Bonne SSEi with the same problem, however a new CKPS fixed it. Seems like A LOT of 3800 powered cars have this problem. Need advice please, anything helps!

As I read your post it brought back memories of my crank sensor failure on the 97. Being intermittent it'* a serious pain in the butt because when you want to test, it will run great.

Try cleaning your battery cables at both ends, the coil and icm bracketry to ensure good grounds and any grounds you can locate. I believe your main ICM ground is located right behind the ICM.

I had a same exact problem with my 2001 SSEi and it would stall on the girlfriend, not me until one day it finally throw a code, i think it was P0334, Crank Shaft Position Sensor. I replaced it for $33 (NAPA i think) and Never stalled on me OR her. No more Check engine light. She is still running good until today.

this thread might be of some help to your problem.

https://www.gmforum.com/t236375/?highlight=dies