Mazda 6 P1487 and P2227

So I have a Mazda 6 showing the above codes. Mitchell wiring diagram shows 2 boost EGR sensors, 1 with 3 wires (I think this is the barometric sensor) And then one with 2 wires. Which I think is the EGR boost solenoid. I changed the Barometric sensor as it tested bad. i.e. I tested ref voltage, ground and sensor all tested good.
when unplugged
Ref was 5 volts
ground was 0
sensor went to 5 volts Barametric pressure hit a high 195 KPA (I may have this reversed)
when sensor jumped to ground KPA dropped significantly
but when plugged in with a vacuum or with out sensor showed 96KPA
with new sensor we now show 26 KPA

I cleared codes after replacing BARO sensor, and it went 5 drive cycles before light came back on. With exact same codes. Really beginning to think there is a random short in one of the EGR boost wires

Believe PCM wants to see B+ from the EGR boost solenoid.
So your probably on the right track.

For clarity, this is the 3.0L V6, right? Model year? Dunno if it matters. *shrug*

Both codes come back? If so, I'd be inclined to chase the P1487 first. That's for the EGR Boost Pressure solenoid, correct? A failure there can definitely impact the operation of the Boost Pressure Sensor. Plus, Mazda solenoids fail like it's their job. :lol:

I'd start with some resistance and bypass tests at the solenoid itself. It's normally closed, so the two ports shouldn't have airflow between them when not energized. Energize it and check for airflow. Cycle it a few times to see if you can catch it acting up. I dunno how much resistance you're looking for offhand - I'd expect around 50 ohms.

FWIW, I suspect this code took a few trips to reset because Mazda has traditionally been very picky about how and when it runs the EGR monitor. It's not like a Ford DPFE system that'll complete the EGR first. :silly: Lots of closed throttle deceleration from the right speeds is needed to make the PCM happy.

Yes this is the 3.0. And I have tested the solenoid and it works as expected.
So I think this is going to be interesting.
Based on wiring diagram and testing I believe this solenoid is ground side switches.
And when I unplug it. I show 12 colts on the power side.
On the pcm side I show 800 mv with spikes to 5 volts. My belief is this is not right.
So I started testing more. Specifically grounds. And all pcm grounds test fine and do not show the 800mv so this made me concerned that pcm was bad.
But being a DIY guy. I did not want to make that call without more testing. So I started testing other ground side switch circuits. All had the same 800mv with spikes to 5 volts.
Next I started pulling fuses. And low and behold when I pulled the fuel pump fuse we went down to 10-12mv
So saturday I start digging into the fuel pump circuit.
Hoping this is the right direction

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The fuel pump fuse? :huh: You mean this one?



I think you ended up changing the behavior of the ground side controls when you pulled the fuse because you disabled the Main Relay, and probably some power feeds to the PCM.

TBH, I think you're gonna end up going in circles with this ground bias voltage. :silly: All those other outputs work well enough despite the bias, right? So I'd suggest that the voltage is intentional, or at least unrelated to your EGR codes.

I don't have access to SI right now, but I'd love to know the exact set criteria for the P1487. If it's purely a circuit code, then that's one thing. If it starts talking about EGR performance, then I wonder if hoses (and a clogged EGR valve in the intake) is on the table, too.

OK that is very possible. And i have been thinking about why the other sensors are not kicking a code. However I thought my wireing diagram showed that the fuse was not related to main relay so I will check that out again. I did also notice that the EGR valve is warm to touch, just with KOEO, it cools down when unplugged. But I believe this EGR is energized when KOEO
from what I understand and what the scanner (cheap scanner) says it is a short on either the B+ side or PCM side. So it looks to me like it is some circuit test.
i would think with the PCM Ground side switching that I would just see an open so basically ghost voltage. But with the spikes to 5 Volts on the signal side it bothers me.
One other note is with KOEO we hear a relay about every 10 min. it is not consistent but does seem to switch every 5-15 min. I do not think this is related however.
Car runs great. So probably not going to do much till next week on it.

Tyler Looking back at the diagram I have I now see where it does affect the main relay. So very possible this affected other systems. And dropped voltage to a lot of things. Thanks for pointing that out.
Pretty much anything ground side switched by the PCM has the voltage on it. which makes be thing of bias voltages but I thought that was mostly on Positive side switched.
I have confirmed PCM power and grounds are all good. Trying to think through my next steps now.

Same. :lol: I think you should stay focused on the EGR Boost Solenoid, but not sure if the issue is on the electrical side or the plumbing side.

If you open the boost solenoid manually while watching the BARO PID, does it drop to manifold vacuum?

Got to look at the code set criteria for both. P1487 is strictly a output state monitor for the boost pressure solenoid. Wants to see 12V on the control wire with the solenoid commanded off, near zero with the solenoid commanded on.

P2227 is monitored when the PCM opens the boost solenoid at idle. If it doesn't see the pressure drop enough (more than 2 inHg, specifically), then it figures the solenoid or its hoses are preventing manifold vacuum from reaching the boost pressure sensor.

I still say you should stick with the P1487. If you're absolutely confident in the solenoid, then it seems likely there's an open or high resistance in the solenoid wiring.

this is a frickin interesting problem I am curious a solenoid issue or what huaaaahh

Thanks for the reply and this helps. I have to finish up on a Valve Job I am doing. But will start back on this later this week. I am going to focus on the 1487 based on this discussion. I know it at least allowed vacum when grounded. but need to check the baro sensor and see what it does.
Beginning to think the voltage is normal on the ground side when unplugged.

OK So since I have not had time to actually trouble shoot this. I did go out last night and check Codes again on this since the CEL is on. I like to make sure nothing new is showing up.
So now I have A U1900 and a U2516. These may have been there all the time. but I used a new Launch Scanner I picked up. And it exposed these codes which I had not seen with my innova.
Also I noticed the battery is low 12.3 volts. And this is after a 45 min drive home with half of it being highway speeds. So it should be fully charged. Or at least I would think so.
So next steps are to check the battery, and alternator. once complete with that I will perform one of the tests recommended earlier for the P1487 and P2227. And post what I find on Saturday.

Mitchroberson wrote: OK So since I have not had time to actually trouble shoot this. I did go out last night and check Codes again on this since the CEL is on. I like to make sure nothing new is showing up.
So now I have A U1900 and a U2516. These may have been there all the time. but I used a new Launch Scanner I picked up. And it exposed these codes which I had not seen with my innova.
Also I noticed the battery is low 12.3 volts. And this is after a 45 min drive home with half of it being highway speeds. So it should be fully charged. Or at least I would think so.
So next steps are to check the battery, and alternator. once complete with that I will perform one of the tests recommended earlier for the P1487 and P2227. And post what I find on Saturday.

Plot thickens! :lol: Let us know what you find. How's your Launch treating you ?

So far the launch has worked better then my bluedriver and my innova. Still have not learned all the in and outs yet.
But every time I plug it in I learn something new. It graphs pics very well. And exposes a lot more then my other 2 scanners.

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OK I replaced the boost solenoid and cleared all codes. And it has been driven for past 4 days with no CEL, What is even more interesting is both the old and new seem to test the same. both opened and allowed vacuum when grounded. So I am obviously missing something. just have not figured out what yet. pretty sure it is the ID 10 T behind the meter.

Mitchroberson wrote: OK I replaced the boost solenoid and cleared all codes. And it has been driven for past 4 days with no CEL, What is even more interesting is both the old and new seem to test the same. both opened and allowed vacuum when grounded. So I am obviously missing something. just have not figured out what yet. pretty sure it is the ID 10 T behind the meter.

Nah, it's just Mazda trying to throw you for a loop. Probably had more to do with temperature and operating conditions. But whatever, sounds like she's fixed!

Did anything ever come of those U-codes?

So I cleared the u codes. And they have not come back. Probably something I did when testing. We have put almost 500 miles on the mazda. And no new codes. So pretty sure it is fixed.

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Hey Mitch, I've been dealing with this same problem with my Mazda, I have recently replaced the EGR Valve in attempt to get rid of the p2227 code, I have also tried replacing the boost solenoid with 3 other junk yard solenoids, now I know you said you replaced your solenoid and the codes have not yet returned, could you please link me the solenoid you bought, as I am having a difficult time finding one. I am hoping that the three other solenoids i tried were just bad, and I wont have to do any costly repairs to this car, I believe the p1487 may be triggering the other code.

Hey parker17! I agree that P1487 is the code to chase. Is this a hard code (won't clear) or an intermittent issue? For our info, what's your specific YMM?

Ran into this forum while researching this error on my 2004 Mazda 6 V6.

I was getting DTC 1487

I checked the Boost solenoid and it seems to work ok. After applying 12v it opens and closes properly.
I also checked the boost solenoid Connector sie B to PCM pin 47 continuity and it shows 37ohms, not sure if that is an issue.
I did have an EGR valve leak between the actuator and EGR body. I ended up using silicone to seal the space between actuator and EGR. When I did that I started getting P1487 and P2227.

One strange thing I'm noticing is that the EGR actuator is getting pretty hot while the rest of the EGR is cool to touch.

My next step is to replace EGR because of the leak and actuator getting hot.

Was anyone else able to solve this problem?