xa007xa

I have to pass state emissions by the end of the month and I can't get the EVAP Sys Monitor to turn on. I Have the service manual and I've followed the instructions for the last 3 weeks and it still wont turn on. I believe the problem is due to the ambient air temp in Chicago. The pre-conditions are:

-No DTC
-Cold Soak (IAT and ECT must reach a difference of less than 13 degrees)
-Remove and replace gas cap
-Tank between 1/2 and 3/4 full
-ECT must be atleast 19 degrees warmer and no more than 52 degrees than IAT at engine start
-Let idle until ECT reaches 167 degrees
-Rev at 3000RPM for 10 seconds
-Turn on A/C and let car idle for 15 - 50 minutes

The problem is that after a cold soak, the ECT and IAT do not reach the minimum temp difference. Car is kept in a garage. How the hell are you supposed to get the ECT atleast 19 degrees warmer than IAT after a cold soak?

Someone please help! This is the only monitor that will not turn on and I've been rejected twice. Third time I fail and have to provide documentation from a repair shop that it's been fixed.

xa007xa

Wow! not even one reply....oh well.

Turns out I figured it out folks.

If anyone runs into this problem, here's what I did to trick the ECU:

First I let it Cold Soak;
Acquire a rheostat, i.e. a light dimmer switch;
Jumpers;
Need an OBD device that can read IAT and ECT (I have a dashhawk);
Skin the 2 wires on the ECT connector;
Connect a jumper to each wire and connect the other ends to the rheostat;
Keep the rheostat off;
Turn the key to on but don't start;
Verify that IAT and ECT difference is 13 degrees or less;
Turn on the rheostat and adjust the resistance until ECT is at least 19 degrees;
Remove and replace the gas cap;
Start the car;
After about 2 minutes start adjusting the rheostat so that ECU reads close to accurate ECT;
Disconnect jumpers;
Idle until ECT is 167 degrees and perform the rest of the requirements.

EVAP monitor turned on right away :D

I used an old rheostat from a commercial A/C lighting circuit. Initially it did not give me the desired temp difference so I simply modified it by cutting out one of the 2 resistors and using a jumper to connect the first resistor to the terminal. I would think that if you run into the same problem, you could try wiring up 2 rheostats in series...I only had the one and was too lazy to walk to the hardware store...