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Help!!!!! P1640, P1670

02-05-2005, 04:35 PM
Hi, I have pontiac transport 3.8 1995 and I changed the A/C compressor and I don't have voltage in relay, also, when runnng, my car fails, and when I stop it dies. I put the cars computer to test and it gives me the P1640 and P1670 code. How do i fix this problem?, and, what is "DRIVE 1" ,"DRIVE 4"?

02-05-2005, 05:34 PM
OK you mean DRIVER 1 and DRIVER 4

P1640 - Driver-1-Input High Voltage
P1647 - Driver 1 Line 7
P1650 - Control Module Output B Circuit
P1656 - Driver 2 Line 6
P1657 - 1-4 Upshift Solenoid Control Circuit
P1665 - Driver 3 Line 5
P1666 - Driver 3 Line 6
P1670 - Driver 4

I would consider this as a problem related to section B of the QUAD driver that gives electrical commands (driver1 to 4) to the EGR (3 sections) and the TCC
DTC56 is OBD1 equivalent of your codes except it does not tell which specific line is in trouble. (the '95 service manual might tell exactly what devices are connected to Driver 1 and 4)

This code can be set due to problem with the driver itself (improbable) ....but generally by the device connected to it.
Problem here may mean sections of the EGR valve stay open or EGR solenoid sections are damaged ..thus your stalling problems. EGR valve degradation is all too common and that is probably all there is to it. Another option --much less probable, just wait - is the TCC solenoid stays closed and the TCC does not disengage thus stalling the engine when stopping.

SO my first step would be to disconnect the EGR valve (a common problem:front of engine, on the driver side). It is covered normally by a plastic cap and you can easily remove the electric connector.
Try that first and tell me what happens...

02-05-2005, 09:36 PM
About the A/C: here is the control diagram
?!?! what was the reason for the change of compressor?
Some conditions are required for the A/C compressor to engage, first being a refrigerant charge and temperature above 32 (mmm... probably not your problem in Miami lol). ALso be sure the pressure sensor near the accumulator on passenger side of radiator is connected.

02-05-2005, 11:12 PM
Originally Posted by jorgemc
Hi, Here is what I found.

- The pins distribution of conector EGR : One pin (D) is the same of the A/C compressor relay (87,86) and come from fuse IGN (639)
- The fuse is OK but I don't have 12 volts on relay (86,87) and EGR (D).
- I put 12 volts on pin 87,86, EGR (D) and turn on de A/C and it work
- I listen to the EGR work, the sign "Check ing soon" continues.

what do you say about the power?

OK..are u really sure the fuse is fact, did you check the right fuse? The fuse displayed that feeds 639 is not the ign fuse in the FUSE BLOCK (in the glove box): according to the schematic, it is one in the convenience center...under the dash, somewhere below the glove box .
IS that the one you checked? (honest, I did not know there was a fuse is a weird place..tell me what you find!)

now if that fuse is blown, these other devices should be impaired :
-evaporative purge solenoid
-cruise control
- oxygen sensor
That was more than enough for the car to stall....and the check engine light will require several engine cycles to clear.

feeding 12v to 86, 87, you have fed them all! WOW

02-12-2005, 08:28 AM
Originally Posted by jorgemc
- I found the fuse in convenience center, it was broken, I replaced and the A/C is ok.
- I hear the "click" of selonoid when I turn off the car.
- The car continue the problem, it fail and stop.

OK... Notice that since you have run the car with a lot of components out of commission, the computer might have set new improper values that could take some time to correct.
If after that you still have problems, then we will look for something else.

07-30-2007, 09:03 PM
I Have A Code P1665 Driver 3 Line 5 Does Any One Know Waht Does That Mean , , Thank You

07-31-2007, 06:43 AM
Welcome to AF. You are tacked on to a 2 year old thread, please start a new one. Also post year and engine when seeking help.

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