monitors won't reset

hammertime · Post by **hammertime** » 22 Dec 2015, 11:42

I have a '96 850 na that will not reset any monitors. I cleared a trouble code that I caused by unplugging the MAF while the engine was running. Since then the car has been driven for almost 2 weeks around town and 2 highway trips. Took it to my local garage and not a single monitor has reset. No check engine light and no logged trouble codes. Have been driving with an expired inspection for nearly 2 months now. Need to get resolved. Any one ever experience this.

Post by **misha** » 22 Dec 2015, 13:05

They will not reset or they are not ready?

hammertime · Post by **hammertime** » 22 Dec 2015, 17:00

I guess the proper term would be ready. The mechanic expected to see some of the monitors ready considering the amount of driving that had been done since I cleared the codes with my hand held scanner. My scanner simply shows readiness complete Y or N, the mechanic's scanner gave read outs of all the different monitors and not a single one was ready.

Post by **misha** » 23 Dec 2015, 05:05

There is a specific "drive cycle" for these cars which needs to be performed to make monitors in ready state.
Search for "drive cycle" on the forum for instructions.

Post by **abscate** » 23 Dec 2015, 05:35

The EVAP ones don't set easily but if none of them are going ready I think you have a deeper problem than the drive cycle. Has the ECU been messed with at all?

hammertime · Post by **hammertime** » 26 Dec 2015, 12:44

Never touched the ECU. The battery got completely drained recently, wonder if that has anything to do with it.

Post by **misha** » 26 Dec 2015, 12:59

Yes.
Drained battery left ecu without power and reset all it's data to factory settings.It takes a while to complete drive cycle and to gather parameters from every single sensor.
Like i said before....there is a special procedure to speed up ecu to complete drive cycle earlier.With everyday normal use it can last for a while,especially in stop & go traffic.

Post by **abscate** » 27 Dec 2015, 06:33

Keep driving it and report back in two weeks. It does seem long but let's see if you can break my Record of 2900 miles to reset all monitors to ready

Post by **jimmy57** » 27 Dec 2015, 07:41

Talk to the inspection station. Some 96-98 Volvos (and a list of many others) have exemptions granted and they only need to have no stored fault codes.

http://www3.epa.gov/otaq/regs/im/obd/re ... f08009.pdf

You can try to see if at least some will go to complete: http://new.volvocars.com/ownersdocs/200 ... ection.pdf

Post by **abscate** » 27 Dec 2015, 12:24

Hammer...if you are still in Crescent country I'm in BUF area on business a lot and can bring the scanner sometime