Drive Cycles to Clear ECM Monitors? Am I the Only One?

I'm having difficulty finding anyone that knows about this...evidently this Nissan has hard to clear monitors.

Had a dead knock sensor in our 96 GXE (VQ30DE) so I replaced it then reset the ECM. Just drove it 78 miles and tested...no DTCs but the following monitors had not completed: Catalyst Monitor; Evaporative System Monitor; Oxygen Sensor Monitor. I was under the assumption that all you had to do was drive it 60 miles for all the monitors to complete but, after talking to a somewhat helpful mechanic was told that the car had drive cycles that were things like...drive for so many miles at a certain speed, let it cool, and a few other things I can't remember. Apparently each car is different and I'm hoping someone here can point me to what they are so I can get them cleared so I can complete the state inspection. Thanks for any help. Thanks for any help.

Reply to
JW
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I don't know the answer but this related topic may help:

When taking your car for inspection I've been told that if you reset the ECU, you have to wait 2 weeks in order for the car to be able to pass inspection by reading the computer. My guess is that's how long you'll have to wait as well, and I mean wait to check the computer again while driving the car, not just have it sit there, of course.

Hope this helps

CD

Reply to
codifus

I tried to post the Nissan TSB with the drive cycle for the '96, but it looks like it got eaten somewhere. If it doesn't come through, email me & I'll send it to you.

Reply to
E Meyer

I found another problem...it seems the TSB mentions that you have to have a computer hooked up while doing the drive traces to monitor fuel demand or something. How would one work around this? I have a decent Innova computer but, I don't think it can be hooked up while the engine is running, even if it could give the information the TSB want you to monitor. One more thing...how can any sensor on a car tell if you added exactly 4 gallons of gas??? Man, this is getting complicated. Not to mention I waited till the last day for inspection so the car is not legal to drive...and there's nothing I can do about it. There was no MIL so I had no idea the car had a problem. Sure am glad I only own ONE of these models. Thanks everyone for helping.

Reply to
JW

The TSB assumes you are a dealer and have a Nissan Consult system. You don't need the computer hook up to get it to initialized. Just execute the sequence and you should be fine. Do it twice if you want to make sure. Any codes that set without lighting the MIL (like knock sensor) will not fail you on an annual inspection.

Reply to
E Meyer

It will and did, in Texas...I just found out today talking to the inspector, that no more than 2 uncompleted monitors can be present in order to pass inspection.

Reply to
JW

Your drive pattern should follow guidelines in the 1996 shop manual pages EC 47 - EC 50

If you have not yet acquired a manual anywhere, the following may be of interest to you. I know I found it interesting, especially the generic drive cycle advice at the end.

In New York you should take the emissions test anyway so you get a valid sticker, let it test fail, and you get an automatic extension. During that 10 day extension period you will certainly accomplish the System Readiness tests and avoid tickets for having an expired inspection. I hope automatic extensions for a failed test are common everywhere and hopefully exist where you live.

The following is from the New York City emissions inspection pamphlet titled "What do You Mean, My Car's Not Ready?" Hopefully the EPA parts will be applicable anywhere:

"Vehicles perform up to 11 system tests, depending on year, make and model of the vehicle. These tests are commonly referred to as readiness monitors.

"HOW MANY MONITORS HAVE TO BE READY? The US Environmental Protection Agency (EPA) guidelines allow up to two monitors to be in a "not ready" state for model year 1996 through 2000 vehicles and one monitor "not ready" for 2001 and newer model year vehicles.

"WHAT CAUSES A "NOT-READY" REPORT? Causes of a "not ready" report: ? Recent vehicle repairs in which diagnostic trouble codes have been cleared with a OBDII scan tool; or, ? if the battery had been recently disconnected or replaced; or, ? if the vehicle's computer requires a software update; or, ? a pending problem has not yet illuminated the "check engine" light.

"Negotiate with the inspection station to have a technician perform the drive cycles according to manufacturer specific guidelines for a fee you will pay. If you take the vehicle from the inspection facility to perform the drive cycle yourself, the inspection station operator can charge you an emission re-inspection fee, up to the maximum fee allowed for an original emission inspection.

"GENERIC DRIVE CYCLE The purpose of the OBDII drive cycle is to run your vehicle's onboard diagnostics. This, in turn, allows monitors to operate and detect potential malfunctions of your vehicle's emission system. The correct drive cycle for your vehicle can vary greatly, depending on the vehicle model and the monitors that need to be reset. When a specific drive cycle is not known, or drive cycle information is not available from an owner's manual, the generic cycle described below may assist with resetting your vehicle's monitors. However, this generic cycle may not work for all vehicles.

  1. The OBDII drive cycle begins with a cold start (coolant temperature below 122 degrees F and the coolant and air temperature sensors within
11 degrees of each other).
  1. The ignition key must not be left on prior to the cold start - otherwise the heated oxygen sensor diagnostic may not run.
  2. As soon as the engine starts, idle the engine in drive for two and one-half minutes, with the air conditioning (A/C) and rear defrost turned on, if equipped.
  3. Turn the A/C and rear defrost off, and accelerate to 55 mph under moderate, constant acceleration. Hold at a steady speed of 55 mph for three minutes.
  4. Decelerate (coast down) to 20 mph without braking (or depressing the clutch for manual transmissions).
  5. Accelerate again back to 55 to 60 mph.
  6. Hold at a steady speed of 55 to 60 mph for five minutes. Decelerate (coast down) to a stop without braking."
Reply to
George

Wow, to do that one, you'd have to be on the FW with a cold engine so you could get up to 55mph 2 1/2 minutes after start up. I wonder if the engineers were pissed when they came up with this stuff? Thanks for the info.

Reply to
JW

It seems like the simplest solution would be to get them to stick the sniffer in the tail pipe and do the inspection the way they do it for pre-96 cars. I wonder if they'll do it?

Reply to
E Meyer

I somehow managed to get 1 monitor to complete so it passed...whew! What were the Nissan engineers thinking when they designed this?

Reply to
JW

I know this is a bit late but that sniffer is connected to a $100K machines which auto garages hated putting up the money for and getting pitiful return on investment. They much much prefer NOT using the sniffer.

CD

Reply to
Codifus

Around here, if they are licensed to do the inspections, they have to have it, so why not use it?

Reply to
E Meyer

Because the new standard is much much cheaper, quicker, cleaner, you name it. All you need is a PC, software, and an OBDII reader. Scan and done. No reading the exhaust when the O2 sensor in the car has been doing it for you anyway. No expensive dyno equipment either. The old system was ridiculous. I don't even own a garage but I felt sorry for the garage owners having to deal with that for inspections.

CD

Reply to
codifus

The dyno equipment is still there and still required. It hasn't gone away. All inspection stations around here that do emissions testing still have to have the sniffer/treadmill setup because all pre-OBDII cars still require annual testing (at least in this county, and AFIK, all the counties surrounding major metro areas.)

The OP couldn't get his car inspected (in this same state, as was later revealed) using the OBDII way because all the sensors did not show "ready". My comment was simply that, since the testing station already has the sniffer equipment, why not ask them to do it the old way.

I have both pre and post-OBDII cars. It takes just as long to get them inspected using the OBD-II connector as it does with the exhaust sniffer. In fact they park the OBDII cars on the treadmill when they plug it in. The paperwork is the actual time waster.

I think this will all change soon. The state has just come up with a program to offer owners of cars older than 10 years $3500 to put them through the crusher if they buy a car 2 years old or newer.

Reply to
E Meyer

In Arizona if the check engine light is on its an automatic failure - only vehicles pre OBD get the sniffer test (because post ODB cars run so clean it can not be sniffed).

Reply to
common_ sense

replying to George, educationmortgage wrote: I have a 96 Nissan Maxima and was locked out from emissions because my drive cycle had not been completed on my vehicle. I drove the generic drive cycle and also drove the car 55 mph for a minute - let go of the accelerator and coasted for 15 secs. and repeated the acceleration and coasting three times. I had driven the car for two whole days for approx. 89 miles when I got the emissions testing again. They told me that they would not do the old style testing if there was a problem with the OBDII reading. I passed. The drive cycle worked. Hope all of you are help as much as I was from this information.

Reply to
educationmortgage

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