mitchdakid

Ok so trying to get my 04 smogged, when we take it to the smog station the guy is telling me that it won't read the computer. Just installed new battery and he says I need to drive a consistent 100 miles to get the battery to reset and make it possible to read the computer. Has anyone heard of this, or know what is going on and why it will not read the computer? I have had this happen two places? Thanks for the help.

Mike Sigmond

Yes, your vehicle need to complete its drive cycles to set the computer to your driving habits & perform system checks, sometimes it can take a day some take a week. There are drive tests that can be done to get it completed faster, I can look it back up if you would like, I posted one here a while back.

Here ya go... I always use an open road where traffic is minimal.

General Motors Driving Cycle

<SMALL>A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.</SMALL>





<SMALL>To perform an OBDII Driving cycle do the following: </SMALL>

• <LI type=disc><SMALL>Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
  </SMALL>
• <SMALL>Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
  </SMALL>
• <SMALL>Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
  </SMALL>
• <SMALL>Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
  </SMALL>
• <SMALL>Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
  </SMALL>
• <SMALL>Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
  </SMALL>
• <SMALL>Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
  </SMALL>
• <SMALL>Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.</SMALL>