Secondary air injection monitor will not run!

[adamcarp]

any new updates on this topic that overs have had success with. I have driven 100's of miles and replaced both upstream O2 sensors, both air pump check valves and been through the drive cycle numerous times. Still cannot get the secondary to run a test and clear the monitor.

[Mike GMC]

Not sure, but could that meat atmosphere, meaning a leak?

[MonkeyWrench]

On 1/25/2016 at 11:38 AM, 2000CHEVYBEATER said:

Hello Everyone

I just joined to share my recent experience with a 2000 Silverado. Everything is related to this thread and some of my actions where guided by info on this thread.

So the truck sat unused for a long time and the battery went dead, beyond recovery. Installed new battery and took to get smogged in N. California on December 22nd 2015 - truck would not pass because "OBDII MONITORS NOT READY". The tech gave me a print out of the required drive cycles and I left and then performed them several times. I brought the truck in and all had reset except "Secondary Air System" Between December 22nd and Jan 21st 2016 I brought the truck back to the smog station 4 times and drove a total of 1300 miles - but Secondary Air System always showed not ready.

January 21 I gave up and brought the truck to a chevy dealership who had a Chevy certified "Master Tech" on staff who had worked on several other chevys with same problem. I passed on info from this site regarding using the Tech II tool to reset the sensor.

So day one he checked the computer which was working fine and did not need any update. He noticed the engine temp reads would not go below 82 deg F even after the truck sat idle for 4 hrs so he thought maybe a sensor need to be replaced but could not be sure until he let the truck sit overnight to give it a chance to completely cool down...

Day two, engine temp read out was 51 deg F. Tech took it for a test drive and notice the engine temp never went over 160 deg F. The tech stated the trucks computer would not run the Secondary Air diagnostic until the engine temp reached operating temp over 200 deg F. He pulled out the old thermostat which was working but was out of spec for this application and put in a new thermostat with correct operating range - test drove again and returned to shop and hooked up to monitor - all Monitors showed ready!! On Monday Jan 25th the truck passed CA smog.

So in summary : an out of spec thermostat that some idiot put in cost $770.00 in diagnostic/repair charges. (could have been worse because I took out a rental car from the dealership, but they didn't charge me) and a full month of frustration and gas money since the truck is not really a daily driver but more of a Home Depot weekend truck..anyway

Hope this info will save somebody the frustration.......check your thermostat!!!

I had a 160’F thermostat and the 2A monitor would not set.  I replaced it with a 187’F thermostat and completed a drive cycle.  The secondary air system monitor set “ready”

 

[boydsc331]

On ‎2‎/‎4‎/‎2018 at 7:53 AM, adamcarp said:

any new updates on this topic that overs have had success with. I have driven 100's of miles and replaced both upstream O2 sensors, both air pump check valves and been through the drive cycle numerous times. Still cannot get the secondary to run a test and clear the monitor.

Here's what I did. I was in the same situation as you, both check valves replaced, I could hear the pump come on at start up, did the drive cycle numerous times over 3 weeks.  I knew everything was working as it should I had a scanner and could see the o2's go lean when the pump was commanded on, I could see the fuel trim go up when the pump was commanded on. I drove 500 to 600 miles trying to get it to complete but it never did.  One night I drove for 20 mins at 55 and still nothing.  I got off the freeway and cleared the codes while I was driving, got back on the freeway and drove 55mph real easy with very little load on the engine and within 1 min the secondary air monitor was complete.  So the next morning I did the drive cycle from cold start to get the o2 heater monitor , and the catalytic monitor to complete and I was done.  I think what happened in my case and a lot of others is the computer does a passive test at first start up when its cold, if it passes that test it doesn't run the test again during that ignition cycle so it never completes because I don't think the passive test completes the monitor it only checks for problems in the system.  So by clearing the codes while I drove it also cleared everything else in the computer memory and it didn't see a passive test so it ran the active test which is whats needed to complete the monitor.  At least that's the only thing I can think of .  Let me know if it works for anyone else

[Amccann]

1 hour ago, boydsc331 said:

Here's what I did. I was in the same situation as you, both check valves replaced, I could hear the pump come on at start up, did the drive cycle numerous times over 3 weeks.  I knew everything was working as it should I had a scanner and could see the o2's go lean when the pump was commanded on, I could see the fuel trim go up when the pump was commanded on. I drove 500 to 600 miles trying to get it to complete but it never did.  One night I drove for 20 mins at 55 and still nothing.  I got off the freeway and cleared the codes while I was driving, got back on the freeway and drove 55mph real easy with very little load on the engine and within 1 min the secondary air monitor was complete.  So the next morning I did the drive cycle from cold start to get the o2 heater monitor , and the catalytic monitor to complete and I was done.  I think what happened in my case and a lot of others is the computer does a passive test at first start up when its cold, if it passes that test it doesn't run the test again during that ignition cycle so it never completes because I don't think the passive test completes the monitor it only checks for problems in the system.  So by clearing the codes while I drove it also cleared everything else in the computer memory and it didn't see a passive test so it ran the active test which is whats needed to complete the monitor.  At least that's the only thing I can think of .  Let me know if it works for anyone else

Response to post by boydsc331

     I had a very similar solution.

I parked next to the the highway and turned the engine off to reset the codes.  The scanner manual warned against resetting codes with the engine running.

I started the engine, then immediately (while the secondary air pump was still running) get up to 60 MPH and held for a couple minutes.  I saw the secondary air become ready in under a minute.

     The secondary air pump runs every time I start my vehicle for 30-60 seconds.  I haven't tested to see whether clearing the codes is really necessary or if getting up to 55-60 MPH while the air pump runs is enough to satisfy.

I think we are onto something here.

[R0B]

I had the same issue with my 2000 Silverado 5.3L and I couldn't get that "secondary air injection" OBD test to clear so I couldn't pass a CA smog check.

 

After doing several cold starts for 2.5 minutes each, I realized the problem. My truck's fuel sender unit is bad and the fuel gauge jumps all over the place when the truck is idling; more often than not, it falls to "empty" and the low fuel light comes on. The system requires there be between 1/2 and 3/4 tank for the OBD to run and I noticed on each cold start, the fuel gauge  dropped to empty during the 2.5 min. 

 

Not wanting to drop the tank and replace the fuel pump, I decided to just rock the truck side to side for the cold start and continue rocking it for 2.5 min because this prevents the fuel level from dropping. I did this for 4 cold starts just to be sure and IT WORKED!!! All OBD are set and my truck just passed smog.  For me, it was important to rock it side to side prior to starting the ignition so the gauge wouldn't start off at empty, then reach in and start the truck and continue rocking it for 2.5 min. 

 

Hope this helps someone! 

[2001gmcsierraht]

^{Hello Everyone.... I have 01 GMC sierra 4.8.. truck has 150k miles on it.. Runs perfect.  Because i dont drive often i unplug the battery for extended periods of time.   This caused the same problem with smog that everyone was talking about "2nd air not ready".. I tired the GMC drive cycle at least 15 times nothing would work... What did work was this suggestion :}

    ADD THIS TO YOUR DRIVICLE, it worked for me.  Park next to the the highway or open road and turn the key off.  Start the engine, then immediately (while the secondary air pump is still running) get up to 60 MPH and hold for a couple minutes.  I saw mine become ready in under a minute.

     The secondary air pump runs every time I start my vehicle for 30-60 seconds.  I recommend doing this before the engine is up to operating temp to ensure the air pump runs while getting up to speed."

 

best of luck.. i know this is very frustrating.

^"

[Michael Anderson]

I have a 2001 GMC Sierra 1500 with this problem.

 

I created an account just to answer it because I was unable to pass secondary air and it drove me nearly out of my mind. I had two problems that I had to correct in order to get my secondary smog to pass. Took me 3 months to figure out. The process I went through was as follows. Hope it helps someone else that cant afford a new truck.

 

In case you dont want to read details below. Make sure air is getting into your exhaust pipes, and then take it to the dealer for new smog software. 

 

My detailed process is as follows: 

1. Checked to make sure the secondary air motor was working and turning on at a cold engine start. It only runs for the first 3 minutes after a cold start. I could hear the motor turning on and off.

2. Removed the secondary air lines connected to the exhaust pipes to see if they had blowing air.

3. I started the engine cold and noticed no air was coming out.

4. Worked my way back to the air source so I replaced the check valves just in case ($30 each on amazon). If you do this make sure you remove the metal lines completely and soak threads with WD40 since the valves are really hard to remove.

5. Waited a day and then checked to see if any air was coming out of the large valve located right after the secondary air motor. This is not the check valves. It is another valve that prevents exhaust from blowing into the fan motor. This valve is controlled by a vacuum line. I noticed that no air was getting past this valve.

6. Checked the vacuum line that opens this valve. It is connected to the manifold. I noticed it was completely rotten with a big hole. I was pretty sure this was my problem and wished I had seen earlier. I replaced this with some rubber tubing I had laying around.

7. Did another cold start test and the valve now opened. So  air is for sure getting pushed into the exhaust pipes.

8. Drove for month figuring it would eventually pass secondary air but it never happened.

9. Grabbed an OBD monitor and reset everything. Did the famous "drive test" and drove hundreds of miles. Everything else passed except my darn secondary air.

10. Gave up and took it to the dealer for an assessment. They said a lot of people were having problems and that it may just need new smog software downloaded to the cars computer.

11. They charged me $150 for an evaluation. The next day they called and said all smog tests were passing. They claim they didnt do anything, but Im pretty sure they downloaded new smog software.

12. Took it back to the "smog only" shop (have to do this in california) and the guy laughed and said the dealer just charged me for updated the smog software and that they are supposed to do this for free.
 

 

 

Edited September 7, 2019 by Michael Anderson

[johnsnowkornar]

On 6/2/2015 at 7:04 AM, Williamsauls said:

I have heard that a tech 2 tool can set the monitor to ready. I would like figure this one out without manually setting the In ear monitor. I can't go to the dealer every time I disconnect they battery. I would think there is some underlining cause for the monitor not run its tests. I'm going to try these items tonight

1) Disconnect the battery and ground out the positive cable.

2) Clean the mass air flow sensor.

 

Fingers crossed...

I didn't propose heading off to a seller each time you disengage the battery, you may of by one way or another misconstrued the post?

 

[Eric A]

First and Foremost, I just want to thank this Forum and the members that participated in this Thread.

 

Today, after three years of dealing with this issue, i was able to smog and register my 2001 Silverado and drive it LEGALLY without a temp permit!

 

I Read all these threads back from 2015 and noticed that i tried everything that others mentioned to do, prior to reading this thread and spent over $1000 in parts and labor to no avail.  To those of you that are at your wits end, here is what you should do and i will testify that it does work, not only on my truck, but my friends 2002 Tahoe.  Just follow these notes and dont give up.

 

Go to your DMV or local AAA office and get a free Temp Moving Permit.

 

Get a scan tool (I used a Innova 3160b.  Plug in and turn on key.  If the "Air" Icon dot is blinking, this means your Secondary Air Pump is not ready to test, therefore you cannot initiate a smog test.

 

Drive to an open long stretch of freeway/highway and safely pull over and shut off engine/ignition.

 

Turn Key on and "Erase" all DTC codes.

 

Initiate "Live Data View" and scroll to MPH view.

 

When safe to do so, accelerate to 55 MPH and lock in your cruise control and maintain speed.

 

SOMETHING WEIRD HAPPENED: some members on here stated their AIR icon disappeared under a minute and thats great if it does.  Mine didn't for over 15 minutes.  I got frusterated and pulled over and drove to a local gas station to get a Slurpee and turned off ignition.  Took a swig of the sugary drink, decided to erase DTC's again.  When i hit the "OK" button, i realized the ignition was still off and the scanner told me the link was disconnected.  So when i turned the ignition back on, i saw that the AIR icon was SOLID!  It worked!  Dont know if it was because i needed to turn ignition off or not or if I needed to have a Cherry Sluppy in my hands but this damn thing worked!!!  I just needed to drive a couple of drive cycles to finish resetting the HTR and EVAP icons/codes and this puppy was ready to smog!!!!

 

That was yesterday (Sunday) and now today took to smog shop, they verified it was ready, passed smog, went to AAA and get truck registered and new tags are on!!!!!

 

Gotta love this fancy internet fandango gizmo and the members that do weird shit and pass it forward.

 

THANKS AGAIN TO THIS FORUM AND THE MEMBERS THAT DO WEIRD SHIT!!!  PASS IT ON!

 

ERIC

 

[gyroplane]

From what I understand, at least in my faithful 2.5 vw, is the additional load from ac, defroster, and headlights allegedly smoothes out electrical pulses during cold start that can affect the knock sensor readiness monitor.

[Rafael Alcala]

I have a 2001 chevy tahoe i fix all monitors but one . Air injection system i replace a air pump new check valves and pump selenoid and still 

Monitor is not ready

[geohacker]

I have a 2000 Silverado 1500 5.3 and I went through the same agony with the secondary air for over 18 months. Did all the exercises I was told to do, but all in vain. I finally tracked down a retired guru from GM who worked in the electronics side of the company  and he informed me that from 1999 through 2002 the V8 engines had to run hot (190 degrees) in the first few minutes to close the loop on smog checks. The ECM had to see the down stream 02 sensors in a hot mode to tell it that it was burning off the carbon emissions. It was a crude system but it satisfied the AQMD people. He suggested that there could be three things that could affect the " task " completion and those were #1 THERMOSTAT....check and see if it's jammed open or a mechanic has replaced a high temp thermostat with a low temp. This situation caused more that 70 percent of the problems and a butt load of other bad readings...like EGR valves. #2...02 sensors should last about 200,000 miles. Test them with an OBD tester to see if they are reading OK. # 3....Catalytic converters go bad eventually and don't burn off the carbons, leading to the down stream 02 sensors giving low temp readings.

He told me to check the thermostat FIRST....and BINGO, some dumb A** mechanic had put in a 160 degree unit when it should have been 190. I bought a 190 and replaced the 160 unit and 3 minutes after starting the engine the secondary air completed and 15 minutes later the catalytic completed. Smog checked perfect the next day.