Auto Code

Just dropped a used 3.4L engine into my 95 chev. lumina 4 dr sedan. Getting service engine light now and then checking computer code getting p-1640code and haven't been able to fine this code in my book, anyone know what this code means?

Reply to
photo1
Loading thread data ...

Reply to
Shep

Reply to
Shep

P1640 is the QDM "A" driver error. Got that on my '95 a couple of years ago. Related symptoms are: TCC inoperative, Full-time vapor purge (high/rough idle), cooling fan 2 always on, oil level light always on. There's a whole flow chart to follow in diagnosing it. For me I just disconnected the PCM, coated the connectors in dielectric grease and reconnected. Haven't had that code back since.

Shep - FYI, the '95 3.4L DOCH is OBDI, but not in the traditional sense. Through '94 and '95, most GMs (as far as I believe) are this ALDL8192 OBD. On F-bodies and other LT1 engine vehicles I believe it goes all the way back to '91. They give P codes like OBDII does.

Reply to
Steve Mackie

Other questions need to be asnwered along with Shep's:

Was the original engine a 3.4? Is it a 3400 or a 3.4 DOHC? When you replaced the engine did you replace the PCM or PROM with the engine? Did you just replace the long/short block, or everything including all sensors and electronics? Is the engine new/used/rebuilt? Did you keep your original trans or replace it as well? Did your car happen to originally come with a 3100 mated to a 3T40 (i think that's the 3-speed) trans and you replace the engine and PCM with the engine and PCM from a 3.4L DOHC that was originally mated to a 4T60-E? When you replaced the engine did you double check that you plugged everything in?

Steve

Reply to
Steve Mackie

Reply to
Shep

F'in car. Getting worse. The "bucking" is really bad now at highway speeds. The motor mounts seem worn but not broken. Something I did notice last night, it's the first time I've driven in the dark in months, the headlights and dome light flicker. When the engine feels like it "comes to life" the light stop flickering and glow brighter. Odd.

Steve

Reply to
Steve Mackie

Reply to
Shep

The replace engine was a 3.4 Doch v-6 and was replaced with the same engine bought used at a junk yard.The pcm and prom were replaced also nut did not replace all the sensors or electronics.Have kept replaced engine with blown hwaed gasket in case I need senors or elctronics off it.Have kept original trans.Re-checked every thing pluged in. Car does not idle rough and I only get ck engine light when load is applied.When car is idling heat sensor will move pass mid-mark but fan turns on and heat indicator will back to normal range.If car is at idle and AC is on heat indicator stays at normal range?

Reply to
photo1

Try putting your original PCM back in, but put the PROM that matches the engine in it.

Steve

Reply to
Steve Mackie

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.