I was driving home the other day (interstate) and the SES came on and it has stayed on up until yesterday when I was driving back from campus. Anyways, I got the thing scanned at autozone and it's a manufacturer specific code.. meaning that my stupid chiltons is worthless. All the autozone guys could tell me was some cryptic message that came up when they entered the code into their computer. It was something about excessive fuel pressure and "can link". Can anyone better explain WTF a code 1642 is? The car is a 96 obdII btw. Also my mileage just dropped about 2 - 4 mpg and I just got the car programmed. I know that could be unrelated but...

Anyways, I'm gonna take a wild guess here and say it's the fuel pressure regulator seeing as how the code mentions excessive fuel pressure.

What're everyone's thoughts? If it is the FPR where is the thing and how do I replace it?

Thanks,

 

The code is for the control circuit for fan relays 2 and 3. One of those relays could be bad or something wrong with the wiring. If the SES went back out, the problem went away for now. If you have a manual fan switch, it can cause this code.

 

The code is for the fan switch relays?! The idiots at autozone indicated it was a fuel system problem...

Well I do have a manual fan switch and have for sometime now and I've never gotten this code before - it's the switch that uses the dual speed setup and the two led's to indicate when the fans are on. It's not supposed to throw any codes...

I did check the fan fuses under the hood and they were fine. I pulled the fan relay out and looked at it then plugged it back in. Like I said before the light is off now. If I get this code again what should I do? How can I test a relay? If I get this code does that indicate that my fans are not coming on? The temp didn't rise or change at all so I'm assuming the fans were functioning at that time.

Thanks for the info shoebox - I gotta admit, you're kinda the electrical/pcm god here on this board

 

Is it a home-made switch or store-bought? If home-made, use this diagram and add the 47 ohm resistors.

If the pcm senses that the voltage condition on the relay activation wires is not correct it can throw the code.

 

that's exactly how I have it wired up.. maybe something has come lose? I'll have to take a look at it.

Thanks again

 

I would check your work. It appears it is intermittent if the SES is going back off.