The dreaded P0410 code

[ChevMali99]

First off - I'd like to say hello to everyone here.

As my ID says I own a 99 Chevy Malibu. I like the car in spite of having, for the past three years two dreaded P0410 codes. One of the two said pending along with the MIL on. For the first two years my mechanics were able to pass my car on basic shenanigans. I couldn't ask them for the hook up for a third time, so I shelled out some bucks to take care of it. The bucks didn't get the job done.

I invested in a OBDII reader and immersed myself in finding out about this code. I connected and disconnected the air pump, EGR, the Evap Canister, along with their respective sensors, and after reading the codes each action caused, I came to the realization that all these items - for all purposes intended - worked fine. Though the evap test always returned incomplete, it was still puzzling to get the dreaded P0410 code. Are the evap, the secondary air injection, and the P0410 related? uhmmm.

I figured going back to basics by pouring 93 - 94 Octane gas along with fuel enjector cleaner, and to my shocking surprise the MIL shut off along with one P0410 pending code. Now, only one P0410 remains. I'm going to see if by filling up with premium gas mixed with a bottle of Heet, gets the last remaining code off and the car ready for testing... oh yes - Im due for inspection in 3 weeks and the car "is not ready for testing".

[ChevMali99]

Much to my chagrin, the MIL is back on along with two P0410 codes. One is already in and the other one is pending. I read somewhere here something about disabling the air pump fuse. Is it that simple to make the PCI not look for the air pump? I'm gonna try that and see what happens.

[maxwedge]

That will not work, the pcm will still try and command the pump on, when it looks at the related inputs and sees no changes as it would be programmed to see, the code will set. If the pump runs, then the problem is usually the solenoid/check valve, water gets in there and seizes it.

[ChevMali99]

Originally Posted by maxwedge

That will not work, the pcm will still try and command the pump on, when it looks at the related inputs and sees no changes as it would be programmed to see, the code will set. If the pump runs, then the problem is usually the solenoid/check valve, water gets in there and seizes it.

hey thanks for the reply - what and where is the solenoid/check valve in the malibu 3.1L "J"?

[ChevMali99]

I think I'm gonna have to kiss NYS, the emissions inspector's, and subsequently the mechanics ring. I figured out how to take the vacuum control solenoid off the car. It's a simple but very delicate process because the plastic and rubber hoses are extremely delicate. Take into account that they are relatively old, thin, and can (and will) break in less than warm temperatures.

Here's what I found. The GM geniuses have places the wires that connect to the air pump in right under, or around, the coolant reservoir. The spot tends to be too tight and, as it appears to be in my case, the pump to work sporadically and intermittently. I guess there's a short somewhere. Also, aside from the main connection to the (I guess) exhaust mannifold, there are two or three wires/hoses whose diameter is smaller than a WD-40 straw that are supposed to route the air blown into the vacuum solenoid to the engine and the EGR. Here's the GM genius at play, presuming that as engines age performance needs adjustments, how on earth are hurricane winds supposed to pass through a straw? In a sense that's what's happening in this transfer of air. The pump blows air at a rate comparable to a fan set on high, through three straws. Granted, in their infinite wisdom, GM must have known what they were doing, and I am not a trained mechanic to know better - so take this with a huge grain of salt.

The P0410 continues to make life miserable and betray what is other wise a sturdy and reliable car.

[ChevMali99]

Update - The standard issue answer to the P0410 problem, "moisture gets into the air pump and freezes etc etc etc." is improbable for the Malibu 99 3.1 J. Also improbable is the vacuum control regulator freeze/stuck either, since it has no valves or flaps to open or close. I took mines apart and it cost me $30 at a junk yard to replace.

Two possible points of exploration are: bad connection to the air pump since it shuts off and comes back on once I jiggle it a bit. I took a multi-tester and found out that current is constant in the wire going to the pump but not after the connector. uhmm. The other is a bad EVAP sensor. I don't know where that one is. The book eludes to an EVAP purge valve of sorts behind the engine but I disconnected the immediate sensor and it shot a P0440 code. Clearly not the idea.

[Schrade]

Originally Posted by ChevMali99

Update - The standard issue answer to the P0410 problem, "moisture gets into the air pump and freezes etc etc etc." is improbable for the Malibu 99 3.1 J. Also improbable is the vacuum control regulator freeze/stuck either, since it has no valves or flaps to open or close. I took mines apart and it cost me $30 at a junk yard to replace.

Two possible points of exploration are: bad connection to the air pump since it shuts off and comes back on once I jiggle it a bit. I took a multi-tester and found out that current is constant in the wire going to the pump but not after the connector. uhmm. The other is a bad EVAP sensor. I don't know where that one is. The book eludes to an EVAP purge valve of sorts behind the engine but I disconnected the immediate sensor and it shot a P0440 code. Clearly not the idea.

Find the EVAP cannister, follow the rubber vacuum line from it to the EVAP solenoid / sensor (probably attached near the motor's air intake, with a vacuum supply from the motor).

[bcopeland]

Run some seafoam through it and see what it does. 2 cans for 2 fillups.

[ChevMali99]

I found this off another site:

http://en.allexperts.com/q/Chevrolet.../OBD-Codes.htm

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Question
I have a P0410 evap code, what does this mean and how vital is the repair


A P0410 is an EVAP code, that has to do with your secondary AIR injection
Here is the circuit description.
Circuit Description

An AIR Pump is used on this vehicle to lower tail pipe emissions at start-up. The VCM supplies a ground to the AIR Pump Relay, which energizes the AIR Pump and the AIR Solenoid.

When the AIR Pump is enabled, the VCM monitors the HO2S voltage. If the HO2S voltages go below a calibrated threshold value, the VCM interprets this as an indication that the AIR System is operational.

When the AIR Pump is disabled, the VCM monitors the HO2S voltages. The HO2S voltages should increase above a calibrated threshold value and switch normally.

If the VCM did not sense more than a predetermined amount of HO2S rich switches, a malfunction will be reported.

The VCM will activate the AIR Pump during closed loop operation. When the AIR System is activated, the VCM will monitor the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR System is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.

The VCM checks that the HO2S voltages return to above a rich threshold when the AIR Pump is disabled.

If the VCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 will set. If only one sensor responded, the VCM will set either a DTC P1415 or P1416 to indicate on which bank the AIR System is inoperative.
Conditions for Running the DTC
• No MAF DTCs
• No MAP DTCs
• No IAT DTCs
• No ECT DTCs
• No TP Sensor DTCs
• No HO2S DTCs
• No VSS DTCs
• No system voltage DTCs
• No Fuel Trim DTCs
• No Misfire DTCs
• No CCP DTCs
• MAF is less than 25 grams per second
• Engine load is less than 34 percent
• Power Enrichment Mode is not active
• DFCO (Decel Fuel Cutoff Mode) is not active
• Convertor Over Temperature not active
• Engine run time after Closed Loop is more than 20 seconds
• Air/Fuel Ratio is 14.7:1
• Fuel Trim counts between 124-132
• Engine speed above 550 RPM
• ECT is between 80-107°C (176-225°F)
• System voltage is more than 11.7 volts
• IAT is more than 2°C (36°F)
Conditions for Setting the DTC

HO2S voltage is less than .222 volt (222 mV) for more than 1 second when AIR pump is enabled
Action Taken When the DTC Sets
• The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.
• The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records.
Conditions for Clearing the MIL or DTC
• The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.
• A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
• Use a scan tool in order to clear the DTCs.
Diagnostic Aids

Low AIR System volume may cause a DTC P1415, P1416 or an intermittent complaint. Also check for the following conditions:
• Pinched, kinked or restricted AIR pipes, hoses or fittings
• Leaks, holes, loose fittings or hoses
• Restricted or obstructed AIR pump inlet
• Leaks or restrictions in the vacuum hoses for the AIR Shut Off Valve.

An AIR supply hose that is melted before the check valve could indicate exhaust gas back-flow past the check valve.

An intermittent may be caused by any of the following conditions:
• A poor connection
• Rubbed through wire insulation
• A broken wire inside the insulation

[ChevMali99]

I poured half a bottle of Berrymans fuel additive "guaranteed to pass emissions" to a full tank of gas and shockingly within 15 minutes all sensors were ready to be tested! Even the P0410 code disappeared! Having said this it briefly returned but then disappeared just yesterday.

[ChevMali99]

Well - the code is solidly back but with slightly different symptoms. The air pump is working fine, but the EVAP sensor has returned to being "test incomplete".

Being that all I need is to pass inspections within the next couple of weeks, short of fiddling with the HO sensors, I'll fill up with premium add the Berrymans thing and hope for the best. At least I know, so far, that the evap canister and sensor works and is capable of completing the PCM test and allow the car to be ready for test without throwing on the MIL.

Maybe next I'll try the seafoam thing and see what happens after I pass inspections.

[maxwedge]

How will these additives affect the evap operation?

[ChevMali99]

Originally Posted by maxwedge

How will these additives affect the evap operation?

I don't know, I'm only guessing from the results I've gotten since I started the thread.

Considering that the immediate need is to keep the MIL off while getting the car ready for testing, it became obvious to me after several occurrences that the additives, in particular the Berryman's, managed to do exactly that.

It got the EVAP testing complete, got the car ready for testing, and the MIL off, for a significant length of time... enough time to get the car inspected, passed, without shelling $500 + and going through the hoops of having real mechanics guess at what the problem behind the P0410 code is. BTW - I wouldn't be surprised if the old tail pipe test passed every single car on the road with the check engine light on.

[Schrade]

Berryman's? Like Nott's Berryman's Farm? They ferment grapes?

There's no magic mojo juice to fix problems. Promise. EVER. NEVER. Negatory. Nada. None. Nope.

Gauranteed to pass emissions? 'Course it is. Cause it's a can of gas. Twice as expensive. And if your motor is tuned, burnin' clean, it will pass emissions. Dump in the mystery juice, and it will still pass (I think )

Try this:

Originally Posted by cbec1999

Find the EVAP cannister, follow the rubber vacuum line from it to the EVAP solenoid / sensor (probably attached near the motor's air intake, with a vacuum supply from the motor).

[ChevMali99]

Originally Posted by cbec1999

Berryman's? Like Nott's Berryman's Farm? They ferment grapes?

There's no magic mojo juice to fix problems. Promise. EVER. NEVER. Negatory. Nada. None. Nope.

Gauranteed to pass emissions? 'Course it is. Cause it's a can of gas. Twice as expensive. And if your motor is tuned, burnin' clean, it will pass emissions. Dump in the mystery juice, and it will still pass (I think )

Try this:

Surely you jest. But the Evap sensor was, as well as the rest of the car, ready for test - or so said my OBDII - after only dropping half of that additive. So the mystery juice 1 - BS P0410 (along with HOS, bad mechanics, and ripoff dealers) 0.

Maybe when I get some bucks to splurge I could help the economy by actually paying a mechanic and allowing him to play musical parts on the car to only have him ultimately tell me "bring it back tomorrow". I'll take my chances with the additive... so far so good.