Hi,

I have a 97 with a 4.2L. In the mornings I sometimes notice the water temp light and the low fuel light lights up for a few seconds then off for a while, then back on again. This happens possibly 3 times, while I'm on the road. This is while the engine is cold. I haven't noticed it when the engine is up to temp, or if it does this if the truck is just at idle. All other gauges read fine and it doesn't matter how much fuel is in the tank. I haven't determined if this is happening every time on a cold start but I suspect it will if it hasn't been. I have a code reader and have replaced the upstream 02's so the only code now is a P0 443, or EVAP sys code which I've tried to trouble shoot myself but need to take it to someone, I've reached my limit of testing ability.

I'm thinking the computer might be going, what do you think?

Thanks,

Devjax

 

It a possibility did you test the sensors in the evolution system their are two dpfe and the vacuum sensor it has a cap on the top of it they both can be tested

 

I guess your truck is newer. My temp/pressure lights are all controlled directly from the sending units (I have analog gauges 1997).
I would check all the connections to the senders, clean them, and tighten them if that applies to you. Could also be the fuse is loose that controls the idiot lights. Check that too.

 

Good idea to check the fuses. I guess it could be anything. Just after I posted the thread this morning I drove to work, it repeated as I described and also when the two lights came on, the fuel gauge 'dipped' and went a bit nuts. All of this stopped in about 3 miles, as soon as the truck reached operating temperature. Weird thing is it did not repeat this in the evening on the way home. Which could indicate that it is also something that is more prone to happen in cool weather. (It's about 50 degrees in the morning now.) Don't you just love intermittent problems?

 

Don't you just love intermittent problems?[/QUOTE]

Sure doesn't everyone?
Definitely sounds like a loose wire or short in the circuit.
Try to get a wiring diagram and see where those wires come together. Probably to a single connector.
If it were me, I would have the ignition on to accessory and wiggle the wires to see if the lights flash on and off.

 

P0443 doesn't seem to be difficult because
1) Only one sensor is involved, Canister Purge Solenoid
2) it is easy to reach, on the firewall, driver side; easy to identify, the green cap device.
3) Basically, either the wiring or the sensor. PCM itself may be bad, but very unlikely. Why don't you start with wiring?