Blackjetvette97

Hi all,
can somebody please inform me as to what this is for? It is found on the driver's side front, next to airbox, and has a hose going into the airbox on it. Mine is constantly coming on every 4-5 seconds and dropping my batt about 2 volts each quick cycle.


Steve

k0ts

I did a search and this thread might answer some of your questions...

http://forums.corvetteforum.com/c5-t...eck-valve.html

http://forums.corvetteforum.com/c5-t...-or-p1416.html

Blackjetvette97

Hi all,
KOts, thanks for the reply and link. I've read through it and can't find anywhere referenced that the pump kicks on and off every 5 seconds, pulling 2 volts down each time it kicks on. It only comes on for about 1 second, then shuts off again. It produces an audible whine and whistle when it kicks on and drops the idle a tad since it pulls power. I don't understand why it would do this constantly. Anyone?

Steve

memphis_vette

wow mine started doing this out of nowhere. what year is your car? i have a 98 c5 a4 coupe. and i thought it was weird but didnt make any effort to look in to it. mine will kick on for about 3-5 seconds then turn off. shortly after it will kick on again

Al Borman

Sounds like it's time to replace your airpump. If your voltage is dropping 2V when the pump kicks on, this means that the electric motor is drawing WAY too much current. And the airpump should not "whine and whistle". Sounds like something is binding up inside the pump, causing the noises and excessive current draw. After running te engine for awhile, can you reach the airpump with your hand to see if it is real hot ?? I think if you raise your drviver headlight manually, you can reach down into the recess and touch the airpump.

Al Borman

Good point about the fuse. The OP should first check for error codes associated with the AIR system. I do not know the power spec. of the air pump, but I do know that if it pulls the battery voltage down by 2V, then there is excessive current draw. Let's say the alt. is putting out 14V, then his air pump is pulling more current than the alt. can supply and as a result, the voltage output drops down to 12V. The on/off cycling is a problem as well. The air system is only supposed to be active during initial warmup, and should turn off when the O2 sensors heat up to proper temp. and become active for the PCM.

The following DTCs can set if a secondary air injection fault is detected:

P0410-- A system flow problem has been detected.
P0412--A vacuum control solenoid control circuit problem has been detected.
P0418-- A pump relay control circuit problem has been detected.
P1415--A Bank 1 flow problem has been detected.
P1416--A Bank 2 flow problem has been detected.

Results of Incorrect Operation:

The PCM detects a system airflow problem by monitoring the heated oxygen senors (HO2S) and Short Term Fuel Trim (FT) values during normal open loop system operation. This is called a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the PCM diagnostic will proceed with an intrusive or active test. The PCM will command the AIR system ON, during normal closed loop operation and under normal operating conditions. This is called an active test. The active test will pass or fail based on the response from the HO2S. A lean HO2S response indicates that the AIR system is functioning normally. An increasing Short Term Fuel Trim value also indicates a normally functioning system. The AIR diagnostic consists of the combination of the passive and active test. It requires failure of the passive and active tests on two consecutive key cycles to illuminate the malfunction indicator lamp (MIL) and store a DTC. If the PCM detects that the HO2S and Short Term FT did not respond as expected on both of the engine banks DTC P0410 sets. If the PCM detects that the HO2S and Short Term FT did not respond as expected on only one of the engine banks DTC P1415 bank 1 or P1416 bank 2 sets.

If incorrect voltage is present on the vacuum control solenoid or the pump relay control circuits the device will not operate. This will be detected by the control module, and DTC P0412 for the solenoid or P0418 for the relay sets.

Blackjetvette97

Hi all,
Guys, thanks for the replies and info. I checked the codes this afternoon already and looked them up on the forum. The only code for the PCM is "P1571" and it is in "(H)History". Nothing "(C)current", except for the one for my TPMS. I also have NOT had the MIL illuminate at all in years. These were all the codes I had listed:

PCM: P1571
TCS: No Codes
RTD: No Comm
BCM: No Codes
IPC: B0521
Radio: No Codes
HVAC: B0361, B0441
AO-LDCM: B2282, B2284, U1255, U1064, U1016, U1096
A1-RDCM: B2283, B2285, U1255, U1064, U1016, U1096
A6-SCM: No Comm
BO-RFA: U1255, U1096, U1064, U1016, C2105(only "Current" code since my TPS has dead batt)

I will check the AIR pump and see if it's hot/working/etc.

Thanks

Steve

WKMCD

Mine was stolen by gypsies..

LS10

Hi Guys,
Did you get to the bottom of the problem with the pump starting and stopping?

We have a similar situation with some differences.

Background.

First of all, I am hoping that it isn't considered "heracy" in the Corvette community to install a Corvette engine into something different.

We have installed a 98 LS1 into an 89 Chevy S10 pickup. We ordered the truck new in Nov. of 88, and with 314K miles on it, it was time for an upgrade. What better than a Corvette engine.....it sure gets the ice cream home from the store before it melts!

We are in Colorado and the state rules are that the truck has to meet the emissions standards of the 98 Vette (since that is where the engine came from), so we brought the emissions equipment over to the truck. As far as I know, the only thing that we changed was the location that the pump puts the air into the exhaust (see below), as our headers didn't have a place to inject the air. Because of that, we got codes P0410, P1415, & P1416. Our interpretation is that since the air is injected downstream of the first O2 sensors, they don't respond to the burst of air, therefore the codes. We had the programmer disable the self test, but not the actual AIR system, so the system would do it's job....but it just wouldn't test the system. We get no codes, but the pump cycles like "Blackjetvette97" above has seen.
One other thing is the vacuum bleed valve. According to the system description, it is electrically operated and is in line between the pump & manifold. We don't have that valve and cannot find ANY wires/connector which could operate said valve. We may have overlooked tha valve itself in the process of integrating this system into our truck, but we used the original 98 C5 engine harness and don't believe that we have overlooked an "extra" connector and wires.

symptoms-
The air pump will sometimes run for a number of seconds and stop. I only notice this while at a stop light and idling. I am guessing that the system is "self testing" , but not sure. The other thing that it sometimes does, is to repeatedly start the pump, stop, start again, and stop again numerous times, maybe 10 or so times. When it does this, it only runs for a second each time, like you hit a momentary switch repeatedly. It runs for so short a time, that the pump doesn't come up to speed. It pulls the voltage down a bit as described above, but the sound it makes when it runs for longer periods doesn't sound bad, just a whirring electric motor. We set the PCM to ignore the self test results, as we relocated the air injection point from the exhaust manifold to the exhaust pipes, in front of the cats and the self test would fail, since the front O2 sensors would not see the burst of fresh air. As the vehicle has to meet the standards of a 98 Vette, we left the emissions as intact as we could. I am guessing that the start & stop that the air pump is doing isn't normal, but hope someone out there knows a lot more than I do.
Your help is appreciated! Thanks

Evil-Twin

You were raised by gypsies.. stolen at birth..

C5VETTE

Hi, new to the forum. Had my 1998 C5 convertible in storage for a number of years, it has 68k miles. I have a code PO410 and I've tried changing out the air pump twice but I am pretty confident that wasn't my issue even though they were both used from eBay, before you judge me buying a new one is a no go as they have been discontinued. I have a similar issue as described in this thread. My air pump turns on for the first few minutes of start up, turns off and seems like everything is fine. The thing is the code comes back on after a day and a half of driving and I have noticed the pump turns off and on while at a red light. It might turn on as I am driving but my Borla exhaust is pretty loud to allow me to notice. A rat did a number on my washer pump wires and MAF sensor wires. I replaced those wires and I have tried to see if there was any other damage done but it does not seem like it. I have taken off my passenger fender to see if those vacuum lines were damaged, but they seemed fine and I came to also notice I don't have an air pump solenoid on my model C5. There are only two vacuum lines going to the air canister instead of three with one leading to the solenoid like I have seen pictures of online. I noticed a 1/4" hole on the right side of my k&n air intake after the throttle body but before the MAF sensor that I closed off, its a molded part of the intake and is supposed to be there but it was open and I did not see a reason for it to be open. I reset the light again to see if that makes any difference but my hopes are low on that prospect. The car ran fine before I put it in storage, it runs fine now but the CEL light remains on. I live in California and will need a smog check soon any help is appreciated. I have read in forums of deleting the reading of the code by the ecu by having a shop with the tuner equipment available to do it. I have heard conflicting sides of doing this and having the car pass smog. I have tried changing out the relay but no luck.

Beer:30

I am having the same issue where it seems to be cycling and drawing lots of current every few seconds. Hasn't caused any problems or codes, it turns off when warm like it should. I really only notice it at night when the headlights are on.
I will check the hoses and valves and see if I find anything.

C5 Diag

The hose that goes into the air filter box is the "clean filtered" air that gets drawn into the AIR pump when it turns on...you can hear the pump quite clearly near the left front headlight !!...mine usually comes on for maybe 20 seconds or so then stops when the engine is cold...it should not be cycling on and off !!

Pounder

dump the whole system !!!!

Beer:30

It's there for a reason to help the cats warm up. I would rather leave it and have it function properly.

Pounder

it's your car, many factory things can be majorly improved !!!!!

Beer:30

Mine acts normally when I turn it on at cold start, it runs without cycling. I noticed today after I drove home 5 miles it was doing it when I pulled in the driveway. It seems to cycle right around 4.4 seconds and is very regular. I don't think it's a problem with the motor or that the motor is not working but something is telling it to kick in constantly. No codes everything runs great, low 20 MPG.
I will keep gathering data and report back. I have Torque pro with ODB reader, any things in there I should be watching/logging?

Beer:30

Sure but then I get into a tune and I just want to keep the genie in the bottle for a DD. I think I only have one more emissions check in 2 years and after that I am free to explore.

C5 Diag

In plain English the paucity of exhaust oxygen at a cold start limits the extent of exothermic reactions in the exhaust port, manifold, and catalyst. The injection of air into the exhaust system therefore could be an effective way to utilize additional thermal and chemical energy available in the exhaust gas for low emissions. The secondary air leads to two types of lambda: “engine lambda (λengine)” and “exhaust lambda (λexhaust)”. The facility to adjust the latter independently of the former eases the calibration constraints. The need to attain stoichiometric fueling as rapidly as possible is relaxed because sufficient air can always be added to compensate for the deficiency in oxygen in the engine-out exhaust gas. The amount of energy available by promoting burn-up in the exhaust with secondary air is surprisingly large. Calculations have indicated that air injection into the exhaust ports can yield as much as 7kW [9]. About one third of this energy went toward heating the exhaust system and two thirds to the exhaust gas. Luminous flames have been observed extending for 50mm into the exhaust [10]. In such conditions it is the HC and CO which sustain the combustion, although it is the hydrogen which is primarily responsible for the ignition. Get it ????...LOL !!

runner140*

I agree....and I did. Commenting on Pounder...dump the whole system.