HETPE3B

Need an advise.
In order to register the car I need to pass the smog/safety test. Since I replaced the ECU I need to drive the vehicle for some time (someone was saying up to a hundred miles) to get the ECU ready for the test. Well, I don’t want to take my chance driving the unregistered vehicle for so long.
My question is - can I lift the rear end and let the wheels spin in the air simulating the driving? Or it needs the actual load or airflow coming?
P.S. Another thing is - when only the rear wheels are spinning - the vehicle doesn’t register the mileage/speed (if it’s important to that application at all).

Rudeney

It's not that you need to drive a certain distance, but that you need to drive under a range of certain conditions that make sure all the sensors are working. The OBDII diagnostic system reports "readiness" indicators that are set during these carious conditions. Most "smog tests" these days plug in a scanner and check for any codes. If there are no codes, then they check that all of the readiness indicators ares set. If so, you pass. The readiness indicators are to keep someone with a problem car from clearing intermittent codes right before the test. For example, let's say you have an O2 sensor error that only triggers over 2,000 rpm. You could clear the code and drive gently to the test center and it would pass, except that one of the readiness indicators won't get set unless the engine revs over 2,000 rpm. Without that indicator being set, you won't pass.

This is the EPA readiness drive cycle:

http://benzbits.com/Drive_Cycle_Readiness.pdf

Most inexpensive generic OBDII code readers will show the status of the readiness indicators so you'll know before you go for the check.

HETPE3B

Thanks Rudeney. I got one of those cheap scanners that can show the readiness status. I guess only 3 indicators are ready. I was in the inspection station and they were the ones that I need to drive that thing before they can do anything. They told me if the indicators are not ready - I cannot pass the test.

HETPE3B

I totally forgot to update with the results. I used this procedure to get the monitors ready (don't recall the website I downloaded them from) on 2 different vehicles (W209 and E90 bimmer). And of course both of them did pass inspection later on.

1. Make Sure the Engine Light is Off
The first and foremost step is to check whether the engine light is off. If your vehicle has active trouble codes, it may stop a monitor from running completely.

2. Check if your Vehicle has a Coolant Temperature
The drive cycle starts with a cold start. The engine coolant temperature of your vehicle should be below 50°C (122°F) and within 6°C (11°F) of the air temperature. You can achieve this by allowing your car to sit overnight.

3. Let the Engine be Idle for 2 Minutes
The next step is to start the engine and keep it idle for two and half minutes, keeping rear defroster and AC on.

4. Drive the vehicle at a Steady Speed of 55 MPH
Now, switch the rear defroster and ac off and keep the speed of your vehicle at 90 km/hr (55MPH) nearly for 3 minutes. During this period, the purge and Fuel monitor diagnostics will take place.

5. Decelerate your Vehicle’s Speed at 20 MPH
Make the speed of your vehicle fall gradually up to 32 km/hr (20 MPH). Avoid touching/shifting of clutch or brake.

6. Again Speed Up
Drive your vehicle back to 55MPH (90 km/hr) at 3/4 throttle for nearly five minutes. The catalyst monitor diagnostics will take place during this period. If the battery is detached or the catalyst is not ready, it might take five complete driving cycles to decide the status of the catalyst.

7. Stop the Vehicle
Now, make your vehicle slow down and allow it to sit idle for 2 minutes.