1996 850 GLT OXS readiness on/off, inspection, intermittent CEL zionx thread from WDYDTYVT diary

[ZionXIX]

More observations today. Started my commute as usual. All emissions codes started as "incomplete". A 20 min drive with a mixture of all driving types in sport mode blasting AC full and 3 gallons of gas in the tank. Catalyst is always 2nd to last to complete and evap completes 30 seconds after I arrive at my destination and idle in park. The process repeats itself on the return trip.

[abscate]

It’s good to be special. That’s sure is way outside the scope of all the Volvo documentation I’ve read.

[ZionXIX]

Evap cleared on a full tank this morning. Posting pictures of my ecu just to make sure I have the right ones.

[dyn blin]

Being in a smog-test state and county, and with the P80's being labled as "potential gross polluters" by our air resources board, I've become pretty consistent at the reset/incomplete/ready cycle. I found this works every time & copied it from an emissions technical resource for our generation of bricks.

Start with the vehicle cool, below 122 degrees F.
Turn off the air conditioning.
Select a location where the driving can be done without violating traffic laws and you can stop safely at the side of the road.

1. Start the engine and accelerate to approximately 1500-2000 rpm.
2. Drive for 6 minutes at 1500-2000 rpm.
3. Stop the vehicle and remain at idle in drive for 70 seconds.
4. Accelerate to at least 45mph and drive for 5 minutes at 1800-2200 rpm.
5. Stop the vehicle and remain at idle in drive for 60 seconds.
6. Accelerate to at least 45 mph and drive for 4 minutes at 1800-2200 rpm.
7. Stop the vehicle and remain at idle in drive for 60 seconds.
8. Park the vehicle and turn off the engine.

This procedure may have to be performed TWICE from a *cold start* to set the readiness codes.

[abscate]

And don’t exceed 60 mph during any of the above, and don’t exceed 3/4 throttle opening, aka light foot driving

[ZionXIX]

I guess I'm just the exception. I drive it like I stole it. Keep it in sport mode. AC full blast the entire time. Codes clear every time without fail as long as I drive a mix of residential roads and highway. Why is my car so different that it refuses to "remember " the cleared codes?

[abscate]

Ah, I’ve figured out your magic.

The ECU waits 17?minutes in between tries to reset the EVAP, and tries three times,before it quits and waits for the next cold start cycle

If you take it for a 15 minute spin, then come back and idle, my guess is the AC isn’t still cold and holds compressor long enough for your idle condition to make EVAP ready. If you drove an hour like, that, my guess is EVAP would not go ready

You are still special, though

[ZionXIX]

The last long trip I took was a 300 mile drive with 1 stop for gas and it did clear.

[abscate]

You are really special.

No clue.

[ZionXIX]

The two starting points for diagnosis testing are:

Electrical part of ignition switch

Main relay ( tucked under the lip of radiator)

So Abscate, I'm interested in pursuing more diagnostics to determine why my ecu is presumably losing power after every key off event. Is power suppose to be running through the main relay at all times?