94 LeSabre Won't Upshift Under Hard Acceleration

[jaimysessanna]

I have a 94 LeSabre. I drive it pretty easy and it's perfectly fine that way. Although when I accelerate hard or push the pedal down and make the car downshift. It sometimes won't shift to the next gear and it'll just stay in that gear for about 7 to 10 seconds. Then usually the "Service Engine Soon" light will come on and it will shift? Anyone have any ideas as to what's going on that triggers this light?


Thanks!

[HotZ28]

More than likely, you have a quad driver fault in the PCM. Quad drivers supply the ground for the shift solenoids. You could also have a bad solenoid, but it is much cheaper to replace the PCM first. You need to find a shop that still has a scanner capable of communicating with the 94 OBD 1.5 PCM and see what the code is. Typical OBDII scanners will not work.

[jaimysessanna]

How would I got about getting a PCM, I'm going to the junkyard tomorrow. Would grabbing one there be good? Say out of a 1993 LeSabre?

[HotZ28]

1993 was OBDI and would not work. IIRC, 94 & 95 are the same, but you will need to change the prom and use the one from your existing unit. You will see a cover on the side of the PCM, remove the two small screws & cover to access the prom. BTW, you can get a rebuilt PCM at O'Reilly with a lifetime warranty for less than 100-bucks. Good Luck!

Edit: I found the info on the PCM/ECM you will need;

#16183247 LeSabre '94-95 Elec Cont Module (ECM); (6-231, 3.8L)
Application: 1994-95 3.8 V6 SFI “L” L27
1995 3.8 V6 SFI “K” L36
1994-95 3.8 V6 SFI supercharged “1” L67
1994-95 truck 3.8 V6 SFI “L” L27

MEMCAL IDs: “L”: BMYU, …
“1”: …
“K”: …
EPROM type: 27C512
16183247