2001 Intrigue - Air Pump ?

Lately the Air Pump in my car has been increasing in speed almost like it has two speeds. It starts out at what I'll call normal speed (a sound that I am used to) and then after a few seconds it will go into what sounds like high speed. It doesn't sound like a bearing is out or anything like that. It just sounds like it wants to go two speeds now.

Exactly what is that pump for and do we need it?

Thanks for the help,

Bryan

Its an emissions device, basically it pumps the stored vapors from your gas tank back into the airstream.

Whether or not its really needed is kind of a subjective term. But more than likely if you remove it you will almost certainly have a check engine light that wont go away.

Mine is rather loud as well, cant say ive noticed the multiple speeds things, but it is louder lately. But it only runs for about a minute, and usually only on a cold start, so its not a huge issue for me.

This pump does not take fumes from the gastank littlhoov. It merely takes air from behind the headlight and pumps it into the exhaust. You can see the air filter behind the headlight. I just recently cleaned mine but it is still loud. I think it is only to help the cat convertor to warm up or work better. PITA if you ask me though.

Well then, I do in fact stand corrected. I tried to tell you guys I dont really know that much haha.

I would hypothesize then, that it injects air somewhere downstream from the EGR valve, because it would seem kind of stupid to inject air into the exhaust stream only to re-circulate it through the airstream via the EGR valve.

It injects air into the exhaust in order to lean out the exhaust gas mixture prior to the O2 sensor so that the ECM will measure the mixture correctly. I know, don't blame me, this is how the powertrain guys set it up so that the vehicle would pass the required 50K mileage emission warranty.:grinyes:

Thanks guys for all the good info. Still makes the two stage sounds but only for a minute or less. Guess it only started since the weather's been a little cooler in the mornings.

Bryan

Well, I'm starting to get the P0410 (secondary air injection malfunction) code now. The pump appears to be working fine. I've taken it apart and there is no water in it like the TSB for this trouble indicates. Also, my gas mileage has taken a sh$#@t. The really strange thing is I feel like I hear the pump kick on while I'm driving and at the same time my lights flicker (in the morning). What I can't understand is what is commanding the pump to come on while driving? The relay looks good so I'm not sure what could be causing this. Could a bad O2 sensor command the pump on?

Mine comes on as well, first thing in the morning, or when cold and then again about 2 to 3 kilometres down the road for a couple short blasts of air. Not sure why, but it does, and yes, my headlights dim quite noticably too.

Not sure why you are getting the code? Is the intake filter for it clogged perhaps? It is located directly behind the left side headlight between the inner and outer fender. I cleaned mine, but did not make the whiney air pump any quieter.

Filter is clean as a whistle. With the pump spinning and all I would have to assume it's good. I've checked the vacuum lines and they all appear to be in good shape (no leaks). With the pump turning one I also have to assume the relay and fuse are both good. I'm wondering if I have a stuck vacuum solenoid. I guess the car has two of them (one left, one right). not sure how to test those though.

Not sure about a vacuum solenoid, but if I remember, there are two solenoids that are on the exhaust manifold in which are hooked up to the air pump and probably open when the pump comes up to speed. Perhaps these are setting your codes. Maybe you can take them off and just clean them?

I'm wondering if I had one that was bad and allowed air to pass by the second and then finally the second one went bad and is now restricting the air flow? I guess I could test that theory by pulling a vacuum on them one at a time and seeing if air flows.

It is not a vacuum system. The AIR pump pumps air and vacuums it in from the filter behind the headlight.

Here's the scenario this morning:

1) Start up car, pump comes on and goes off as usual
2) Driving down road about a mile and lights flicker, pump comes on (40 mph)
3) Let off gas and pump goes off
4) Accelerate to around 40, can hear pump come on again
5) Let off gas and pump turns off

Pump appears to be turning on for short bursts.

What ever (condition) is telling the pump to come on during acceleration or ride down the road is what is causing my P0410 code. urrrrrgh

Yes, that sounds like how mine operates as well. I have tried that scenario a few times when it comes on breifly, but there again, once the car warms up it does not come back on again.

This just started doing this only recently. I'm still wondering if the O2 sensor is going bad and senses a rich or lean condition. All the mechanics that I've talked to say "no they doubt it". So what is it? Something is telling that pump to come back on.

:lol: Mine does the exact same thing. Strange thing is that I just replaced mine with a brand pump less than 3 weeks ago. If y'all figure out the whole solenoid thing post up as I'd be interested in trying it. It could be a sticky if it turns out to be accurately diagnosed and fixed.

Good luck!

From what I've gathered the system is rather simple:

1) Air Pump (hose connects to metal Y pipe (front/back manifolds)
2) Two vacuum driven solenoids (1 on each manifold)
3) Electric vacuum solenoid switch (under and behind top UIM cover)
(Can't miss it, it has two vacuum lines running to it and an eletrical connector)
4) Relay (passenger side just above battery)
5) Fuse
6) some vacuum lines and a couple of hoses.

Now the real question is what would command the pump back on after you start driving.

I have the same problem. I cannot hear the pump come back on while I'm driving, but I assume it does because the headlights flicker. There is a good post on the forum that I think explains this. Based on the info below, it seems the pump comes back on only when the passive test fails causing the PCM to run active tests.

PanzerDragon 7-12-2005 post copy and pasted below:

CIRCUIT DESCRIPTION
The AIR pump is used on this vehicle to lower fail pipe emissions on start-up. The Powertrain Control Module (PCM) grounds the AIR pump relay control circuit, which energizes the AIR pump. The PCM also grounds the AIR solenoid valve control circuit, which energizes the AIR solenoid valve. The AIR solenoid valve opens allowing manifold vacuum to open the AIR control valves. The PCM enables both control circuits when AIR system operation is desired. When the AIR system is active, the AIR pump forces fresh air into the exhaust stream in order to accelerate catalyst operation. The AIR control valves replace the conventional check valves. When the AIR system is inactive, the AIR control valves prevent air flow in either direction. DTC P0412 applies to the AIR solenoid control circuit. DTC P0418 applies to the AIR pump relay control circuit.

DTC P0410 sets if an air flow problem is detected. The PCM will run two tests using the Heated Oxygen Sensor (HO2S) voltage to diagnose the AIR system. Both tests have two parts.

The passive test is performed during regular AIR pump operation. The passive test consists of the following:

Passive Test Part 1
When the AIR system is enabled, the PCM monitors the HO2S voltage. If the HO2S voltage goes below a threshold, the PCM interprets this as an indication that the AIR system is operational.

Passive Test Part 2
When the AIR system is disabled, the PCM monitors the HO2S voltage. The HO2S voltage should increase above a threshold and switch normally.

If both of these tests indicate a pass, no further action is taken. If one of the above tests failed or is inconclusive, the diagnostic will proceed to test two. The active test is performed specifically for diagnostic purposes. Test two consists of the following:

Active Test Part 1
During this test the PCM turns the AIR system on during closed loop operation. When the AIR system is activated, the PCM monitors the HO2S voltage. If the AIR system is operating properly, the HO2S voltage should go below a predetermined threshold.

Active Test Part 2
The PCM turns the AIR system off. The HO2S voltage should return to above a rich threshold.

The PCM will repeat test two up to 4 consecutive times with a short delay between each command.

If the PCM determines that the HO2S voltage did not respond as expected during the tests, DTC P0410 will set.

CONDITIONS FOR RUNNING THE DTC

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0171, P0172, P0300, P0412, P0418, P0442, P0443, P1441 and HO2S DTCs not set.
The engine operates for more than 3 seconds .
Test 1

The engine speed is more than 400 RPM
The engine load is less than 80 percent .
The engine air flow is less than 35 g/s .
The ignition voltage is more than 11.5 volts .
The air fuel ratio is more than 13:1.
The Engine Coolant Temperature (ECT) is less than 40°C (104°F) .
The Intake Air Temperature (IAT) is more than 10°C (50°F) .
The power enrichment, deceleration fuel cut off, or catalyst over temperature not active.
The AIR system is enabled for 50 seconds . On a hot start, the AIR system operation will be delayed for 60 seconds after start-up.
Test 1 fails if:
HO2S voltage does not go below 300 mV for 25 seconds during pump operation.
HO2S voltage does not go above 600 mV during the 15 seconds after the pump is turned off.
Test 2

The engine operates for more than 5 minutes .
The engine speed is more than 400 RPM .
The EVAP purge is active
The maximum air flow is 35 g/s .
The ECT is more than 10°C (50°F) .
The ignition voltage is more than 11.5 volts .
The engine load is less than 80 percent .
The fuel system is operating in closed loop.
Test 2 fails if the HO2S voltage is above 300 mV for 4 seconds during pump operation.
CONDITIONS FOR SETTING THE DTC
If the HO2S voltage does not behave as expected during either of the tests, a failure is reported.

ACTION TAKEN WHEN THE DTC SETS

The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC

The PCM turns the MIL OFF after three consecutive drive trips during which the diagnostic runs and passes.
A last test tailed, or the current DTC, clears when the diagnostic runs and passes.
A History DTC clears after forty consecutive warm-up cycles, if no other emission related diagnostic failures are reported.
Use a scan tool in order to clear the MIL diagnostic trouble code.
Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.
DIAGNOSTIC AIDS

NOTE:

Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.
Refer to Continuous Operation of the Air Pump Notice in Service Precautions.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature, etc., that you observed This will isolate when the DTC failed.

If the problem is intermittent, refer to Intermittent Conditions. See: Diagnosis By Symptom\Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

DTC P0412 AIR Solenoid Valve Control Circuit and P0418 AIR Pump Relay Control Circuit should be diagnosed first if either are set.
The AIR pump is not designed to run continuously. If the pump needs to be replaced, check for conditions that may cause continuous pump operation.

Great stuff. This brings me to think that my O2 sensor may be bad or going bad if it's using the readings from it to diagnose problems.

I tested all of my soleniods and they appear to be working just fine so I don't think there is a air flow problem. Unless of course my fan is "going" bad and not pushing enough air through.

I may have found the source of my problem. I got a vacuum pump from Autozone today (loan-a-tool) and tested both of the vacuum solenoids for holding vacuum. The driver side works great. The passenger side is another story. It won't hold a vacuum, so the internal diaphram must be bad. I'm thinking that since only one solenoid is working it must be restricting the amount of air being sent over the O2 sensor during cold starts. Since the air is more dense during cold weather, it makes sense that the pump isn't moving enough air. I ordered a new solenoid from GMPartsdirect (#12559949) so I should have it in a few days.

This is fantastic! If you do find that is the source of the problem, can you please take pics and post where the solenoids are located? Yikes that solenoid is expensive!

The dealer wants $250 each. I'm trying a test. Since the diaphram in the passanger side one was broken (causing an internal vacuum leak) I disconnected the vacuum line from it and plugged the end. I think the leak was causing a weak pull on the good one which in turn would have caused the good one not to open which would have caused the pump to backup and pump to "nowhere". Now my pump sounds normal and it didn't cycle while I was driving. If this works then maybe I can get along with only one solenoid for a while. I'll know more by the end of the day.

Problem Solved - It was the passenger side solenoid - internal leak (Located directly under the anti-freeze fill/overflow bottle). Removing and plugging the vacuum line allowed more vacuum on the driver side solenoid which opened the valve. No more flikering lights down the street (PCM running active test) and no more check engine light. The driver side solenoid is just to the left of the air filter box. They both have a rubber hose from the "Y" pipe and a metal hose going to the exhaust manifold. You can't miss them. So, get a vacuum pump, draw a vacuum on each diaphram and see which one is causing the problem. May be able to remove and open them up and replace the diaphram? Yeaaaaah.

This is great info! My SES light finally went out on its own! I wonder if the new pump just needed to take some time to 'flush' out my solenoids? Thanks for the location of the solenoids.

Right below the coolant hose is the one solenoid from your description.
http://img75.imageshack.us/img75/5472/35lv6shortstarcr9.th.jpg (http://img75.imageshack.us/my.php?image=35lv6shortstarcr9.jpg)

Your picture shows the exact location of the driver side solenoid (great picture). The passenger side one is just below the anti-freeze fill bottle. My car is still driving great. Good news on your pump. I'd probably still see if your solenoids are holding vacuum.

Wow. You keep things under your hood unbelievably clean!

Your coolant surge tank is way too full btw...

It's not my engine and not my picture. It's good to have reference pics though. I did just replace my recovery tank so it does look clean like that however. My front valve cover paint is all gone and chipped off.

Yes, mine also runs periodically as I'm driving. The first (original) one that was noisy did not run while driving, just the new one that I installed in March. The car runs well......the noise is just frustrating. Wish there was an answer on how to eliminate it.

The noise increases due to lack of air movement. Test the solenoids for holding air (get a vacuum tester from Autozone or like place). Hook the vacuum gauge to the solenoid ports and see if they hold a vacuum. I think you're going to find that one, if not both, of your solenoids has ruptured one of their diaphragms.

Thanks for that suggestion. It makes sense. I'll try that when I get a gauge.