Clearing check engine light
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Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
Further if your car requires an emissions test soon after you clear the code it will fail. Clearing emissions related (CEL) codes also sets the emissions readiness indicators to NOT READY and the car will require a specific drive sequence to reset them to READY so the car can be emissions tested
I found that out the hard way.
Slightly off topic but in regards to what 8VETTE7 said.
I had a LESS than 2 yr old Delco Pro battery crap out on me a couple of weeks ago. Pulled the battery on a Friday, Got a new replacement on Monday and the following day after installing it I decided to take my car for it's yearly inspection . Bad move.
It failed because Emission readiness was not ready. Been driving it on and off now and also ran the 8 step OBD II Readiness Relearn procedure.
I got till the end of this month so I'm not worried. I'm sure by now everything has been reset....I HOPE
Last edited by SG Lou; May 22, 2018 at 06:09 AM.
3rd Gear
Joined: May 2018
Posts: 3
Likes: 0
8VETTE7 is spot on.
Clearing the codes does not fix anything. Plus don't you want to know what has triggered it?
Just go to Advance or Autozone and they will read the code for you. (they won't clear it though).
Or just buy a $20 scanner and read the code and clear it yourself. There is a great guide here if you need help with that part.
To answer your question. Just disconnect the battery for a few minutes and the CEL will be reset.
Clearing the codes does not fix anything. Plus don't you want to know what has triggered it?
Just go to Advance or Autozone and they will read the code for you. (they won't clear it though).
Or just buy a $20 scanner and read the code and clear it yourself. There is a great guide here if you need help with that part.
To answer your question. Just disconnect the battery for a few minutes and the CEL will be reset.
Burning Brakes
Joined: Jul 2010
Posts: 1,210
Likes: 17
From: When Democracy becomes tyranny, the armed citizens will still get to vote!
You don't need to go anywhere or buy anything, the C5 has it's own on-board diagnostics. It's accessed through the driver info center. Lots of posts on how to access and what the codes mean.
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Joined: Mar 2016
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From: Southlake, TX
Safety Car
Joined: Mar 2005
Posts: 3,757
Likes: 1,215
From: Wisconsin
To perform an OBDII Driving cycle, do the following:
1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be
below 122°F and within 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.
2. 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.
3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until
55mph is reached. During this time the misfire, fuel trim, and purge flow diagnostics will be
performed.
4. Hold Steady Speed. Hold a steady speed of 55mph for 3 minutes. During this time the O2
response, air Intrusive, EGR, purge, misfire, and fuel trim diagnostics will be performed.
5. 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 20 mph. During this time the EGR, purge
and fuel trim diagnostics will be performed.
6. Accelerate. Accelerate at 3/4 throttle until 55-60mph. This will perform the same diagnostics as
in step 3.
7. Hold Steady Speed. Hold a steady speed of 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.
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or
brakes or shift gears.
1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be
below 122°F and within 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.
2. 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.
3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until
55mph is reached. During this time the misfire, fuel trim, and purge flow diagnostics will be
performed.
4. Hold Steady Speed. Hold a steady speed of 55mph for 3 minutes. During this time the O2
response, air Intrusive, EGR, purge, misfire, and fuel trim diagnostics will be performed.
5. 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 20 mph. During this time the EGR, purge
and fuel trim diagnostics will be performed.
6. Accelerate. Accelerate at 3/4 throttle until 55-60mph. This will perform the same diagnostics as
in step 3.
7. Hold Steady Speed. Hold a steady speed of 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.
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or
brakes or shift gears.
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Verdad Gallardo
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
To perform an OBDII Driving cycle, do the following:
1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be
below 122°F and within 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.
2. 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.
3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until
55mph is reached. During this time the misfire, fuel trim, and purge flow diagnostics will be
performed.
4. Hold Steady Speed. Hold a steady speed of 55mph for 3 minutes. During this time the O2
response, air Intrusive, EGR, purge, misfire, and fuel trim diagnostics will be performed.
5. 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 20 mph. During this time the EGR, purge
and fuel trim diagnostics will be performed.
6. Accelerate. Accelerate at 3/4 throttle until 55-60mph. This will perform the same diagnostics as
in step 3.
7. Hold Steady Speed. Hold a steady speed of 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.
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or
brakes or shift gears.
1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be
below 122°F and within 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.
2. 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.
3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until
55mph is reached. During this time the misfire, fuel trim, and purge flow diagnostics will be
performed.
4. Hold Steady Speed. Hold a steady speed of 55mph for 3 minutes. During this time the O2
response, air Intrusive, EGR, purge, misfire, and fuel trim diagnostics will be performed.
5. 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 20 mph. During this time the EGR, purge
and fuel trim diagnostics will be performed.
6. Accelerate. Accelerate at 3/4 throttle until 55-60mph. This will perform the same diagnostics as
in step 3.
7. Hold Steady Speed. Hold a steady speed of 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.
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or
brakes or shift gears.
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