2002 - Suddenly get P1430 code w/Check Engine Light

Discussion in 'Generation 1 Prius Discussion' started by TexomaEV, Aug 9, 2014.

  1. TexomaEV

    TexomaEV Member

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    Suddenly today, I get a "Check Engine" light while driving. Scangauge II says it's a P1430 error. I found two different suggestions, both of which I have no idea where these are located on the car. Any help, is greatly appreciated as you guys have always come through in the past.
    P1430-Electric Air Pump secondary Failure
    P1430 -Vacuum Sensor for Adsorber and Catalyst System Circuit Malfunction

     
  2. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Gas cap seal?

    Bob Wilson
     
  3. ChapmanF

    ChapmanF Senior Member

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    The second choice (HCAC vacuum sensor) is correct, the first one about some air pump is off the wall and must be about some totally other car. Where were you looking that up?

    That sensor measures the vacuum in the circuit that operates the HCAC valve (in the exhaust pipe ahead of the catalytic converter). I'm not sure exactly where the sensor itself lives; page SF-50 is where you would look for the replacement instructions (but that's in my 2001 book, pages might be different for your 2003).

    Pages DI-127 to DI-130 (again, 2001 edition) show the diagnostic steps to sort out the possible causes. Basically they have you measure the sensor voltage back at the ECM itself (which is easy to get to behind the glove box). If the reference voltage being supplied to the sensor by the ECM isn't right, then they'll call the ECM the culprit. Otherwise, if the sense voltage coming back is reasonable, they'll call the sensor likely good, and the ECM still the culprit. If the sense voltage is wrong coming back, they'll have you check for wiring damage on the way to the sensor first, and then only if you find no wiring problem, by elimination the sensor is what's left.

    -Chap
     
  4. TexomaEV

    TexomaEV Member

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    Gas Cap is on tight, I will swap with the one on my 2001 to test your theory.
     
  5. TexomaEV

    TexomaEV Member

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    Thanks, I will do some trouble shooting from that if the gas cap idea falls through. Somewhere I have a manual on CDROM - Hope I can find it....
     
  6. ChapmanF

    ChapmanF Senior Member

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    Oh hey, I just looked again and you've got a 2001 also, so our page numbers should be the same. I must have glanced up and seen Bob's 2003 and thought that was what you had. Sorry for the mixup.

    -Chap
     
  7. TexomaEV

    TexomaEV Member

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    No problem, I actually have a 2001 & a 2002. The 2002 is giving me the P1430 error at this time. Thanks so much for your help, if the weather cooperates tomorrow, I'll start troubleshooting if the gas cap didn't fix it. One thing I'm hoping might have done this, now that you explained about the sensor and where it's trying to take it's measurements from, is I recently traveled down a gravel road, of which had several high spots in the center, and I actually scrapped gravel a few times. I plan to drive up on some vehicle ramps, and get under the car to see if maybe I damaged something under there...
     
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  8. TexomaEV

    TexomaEV Member

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  9. TexomaEV

    TexomaEV Member

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    Apology - I'm sorry to say, I've not been able to do anymore troubleshooting to date, due to both weather and working overtime. I promise, once I am able to dive into the problem again, I will post the outcome, be it good or bad. I want to THANK you two for the troubleshooting suggestions, and look forward to resolving this issue. Hopefully the 12 hour shifts will end soon...... :)
     
  10. TexomaEV

    TexomaEV Member

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    Still getting the P1430 error. Valve under the car moves freely by hand, but I am noticing there is no vacuum getting to the valve/plunger down there. Are there any vacuum lines and solenoid diagrams for the 2002 prius? The hose from the vacuum valve under the car seems to be good up to the metal tube which looks like it is going up into the engine compartment. I do not hear any vacuum leaks in the engine compartment, and all rubber lines I can get to are good. I am wondering if there is a vacuum solenoid that either is not functioning properly or not getting a signal from the ECM telling it to open and allow a vacuum to be present on a particular line. Thoughts..... Car seems to run fine, just am annoyed with the error code, and now that my insurance company sees the error with the OBDII plug they supply, I am worried they might not want to insure the car if it is not fixed.
     
  11. Gputah

    Gputah New Member

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    Did you ever figure out what was wrong? I am working on this for my car right now as well. I got this code, and a cylinder misfire code (p0303) at the same time. According to Autozone, a common fix is replacing spark plugs. I replaced the plugs, but the car is running pretty rough and I am getting the misfire and p1430 code still. I have ordered new ignition coils and will try that. They probably are due for replacement either way, since they are original and I have 181k on the car.

    If you were able to find something out I would love to hear what that was. Thanks.
     
  12. TexomaEV

    TexomaEV Member

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    Sadly I am still getting the consistent error. If I clear the error while the engine has shut down, the code stays away, but as soon as the engine starts it pops up instantly. Engine runs fine, drives fine, mpg does not seem to be affected as of yet. I have not found any wiring issues so the task may be to start swapping out vacuum sensors / valves next.

    In your case, I would get under the car and make sure that flapper valve can easily be moved by hand as I wonder if it has frozen in a position causing your rough engine operation.
     
  13. ChapmanF

    ChapmanF Senior Member

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    Have you tried going through the workup steps on pages DI-127 to DI-130 yet? What results did you get?

    Cheers,
    -Chap
     
  14. vtecfed

    vtecfed New Member

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    I just drove my 2001 Prius to the store and came home to P1430 and a P302 codes..after I linked my scan tool and started the car P1431 came up as a "pending code"...any ideas? Thanks guys..
    It's been a great car..it has 124k miles..I drove it from California too Oklahoma a few times..I changed the spark plugs about 5k miles ago..I did let the battery die a few weeks ago but I've driven it a few times since then with no problems..
     
  15. dabard051

    dabard051 Tinkerer-in-Charge

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    I have returned from the land of Mordor, and I have a suggestion regarding P1430. I had it; fault would not clear. The canister moved the HCAC valve freely when the car started, so I knew it was generating good vacuum, no leaks. So it must be electrical. What I found:
    The vacuum sensor which generates this code is just above and to the left of the dipstick. It's held in place on a bracket with two M6 bolts with 10mm hex heads. The Toyota part number is 89421-20190 and says "SENSOR, VACUUM". The vacuum hose (black, about 7mm diameter) connects to the bottom of the sensor. The electrical connector is a push-to-release, and the locking tab is pretty stiff. It has 3 wires coming out - brown, violet and yellow w/red stripe. One of these wires (vellow/red) broke right at the connector and was so close, it looked like it was good - until I replaced the vacuum sensor and found only two wires still intact. So, if you are getting intermittent P1430 codes, apparently randomly, it's a possibility that the wires coming out of the vacuum sensor connector are broken and occasionally losing conductivity. The wires make a 90 degree bend right out of the connector, so they are under stress, and any big hands removing or inserting the dipstick are likely to brush against the connector and stress the wires again. I happened to have a sacrificial Prius from which I snatched a replacement connector. So I cut out the damaged connector, and soldered the wires to the new connector. Start the car, clear the code, and it goes away.
    So here's the electrical check: brown wire is ground; yellow/red is +5v, and violet is (a) 3.6v at cold start (b) drops to 2.0 and 1.6 at various stages of the warm-up. Inspect the wires carefully at the vacuum sensor connection. IT IS POSSIBLE THAT THE WIRE IS BROKEN INSIDE THE INSULATION AND THE INSULATION IS INTACT. In other situations, I have seen instances of broken wires inside an intact insulating sleeve. Use a pin to puncture through the violet wire, and read the voltages as the car warms up. If the yellow wire is broken, the voltage on violet will stay at zero. If the brown wire is broken, the violet wire will read +5v. If the violet wire is broken, the voltage will be zero or some strange value less than +5v, but not the 3.6 or 2.0 or 1.6 as the vehicle expects.
    The repair: I happened to have a connector. It is NOT available at Radio Shack (RIP) or its equivalent. It's Toyota robust, waterproof sealed; the sensor contacts were in very good shape. No corrosion after 17 years. So it failed just outside the connector.
    You can check your work by connecting the wires to the prongs of the sensor with alligator clip jumper cables, taking care to match yellow, violet (middle) and brown appropriately, and see if the fault code can be cleared. If it clears, and stays away, you know that you found the location of the flaw.
    Then what remains is a robust repair. I'm still thinking about that.
    If this gets found by Toyota service, they have to replace that portion of the wiring harness. IF they can find one. Ouch.

    Good luck to all who visit this thread...
     
    #15 dabard051, May 1, 2018
    Last edited: May 1, 2018
  16. ChapmanF

    ChapmanF Senior Member

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    Thanks for the detailed write-up!

    -Chap
     
  17. dabard051

    dabard051 Tinkerer-in-Charge

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    Following up: Toyota does sell the connector shell. HOWEVER: the shell does not contain the wires.
    They have wiring repair kits... but replacing the wires in the shell requires some special tool that I don't have.
    The Toyota terminal repair kit part number is 82998-12340, which is a SINGLE WIRE with one connector on it.
    Each kit fits one prong in the sensor. Price is US$7.48 per kit, at my local dealer.
    If you must discard the shell, you will need 3 kits to restore functionality.
    Weatherproofing: heat-shrink tubing over each connector when you replace the ends.
    CHECK FOR CORRECT OPERATION. Then fill the end of the sensor with RTV to make it water tight.
    This is a suggestion; I haven't done it. Good luck to all.
     
  18. dabard051

    dabard051 Tinkerer-in-Charge

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    Yet more followup on P1430 & P1437:
    Between the vacuum valve monitor (which sets these codes) and the HCAC valve (which in some climates is prone to seizing up), there is a stretch of metallic pipe (which carries the vacuum from the manifold to the HCAC) and, connecting to the HCAC valve, a short length of 8mm OD (1/4 inch OD) rubber hose. After a number of years, this short length of hose is prone to splitting where it connects to the pipe from the sensor, which is ABOVE the HCAC and not very visible. You have to remove the hose from the car to do the inspection. The pipe from the engine has a little bulb on the end, and it's right there that the hose seems to fail by splitting. Seen this twice, now.
    This hose failure appears to be the root cause of my intermittent P1430 and P1437 codes on my 2003 Prius (287k miles). Depending on which way the rubber bent, it would sometimes allow the HCAC to work correctly (the valve was determined to move freely), and sometimes not; sometimes the first code set was a "low vacuum" (P1430).
    So be sure to give this little bit of hose a good looking over; particularly if you're dropping the cat converter/resonator/HCAC valve assembly for inspection and/or repair, if you have either of these codes. It's a $.50 fix to replace it with basic 1/4 in black rubber hose from the hardware or auto parts store.
     
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