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Mazda MPV Electrical System/Lights



  • buzzkbuzzk Posts: 15
    wouldn't be surprised at other causes of running problems - that would be normal enough & I've had other problems to trouble-shoot & fix. [I'll have the fun of replacing the most inaccessable o2 sensor soon - bank 1, sensor 1]. I've gathered from other's comments, etc that the PCV valve [+/or it's hose] can be a problem & might relate to your symptoms. OTOH, w/the voltages generated by ignition coils a small amount of retained, inapparent dirt or moisture can cause mis-firings. It doesn't have to be obviously wet.

    One of the unpleasant jokes some sailors [usually techs] thought of as fun was to lightly run the tip of a sharpened lead pencil to draw a line down the side of the usally black distributor cap [acts as a conductor] from a plug wire to the base of the cap - it was claimed [many swore that] it would cause an impressive mis-fire..

    good luck, BK
  • rollingrolling Posts: 5
    I got impatient waiting for a set of ignition coils to arrive by mail for our 2003 MPV. I got one at Autozone and installed it to correct our second cylinder misfire within a week. (The remaining 4 coils are still the original ones, though I have replacements in hand.)

    With the new coil, the minivan worked fine on short trips for three days. Then 70 miles into a long trip, the CEL came on again. However, the van still seemed to be operating fine. In a few miles, we stopped at an O'Reilly's. This time the error code is P0431 'warmup catalyst efficiency below threshold (Bank 2)'.

    We stopped at a local garage and were advised that the problem could be an oxygen sensor, a failing converter, or just a bit of bad gas. Also, that if the CEL was not flashing and the car had plenty of power, then it was probably safe to drive it. So we did. 400 miles later we arrived at our destination without incident. The CEL never flashed a second time. We are visiting some relatives and are still 500 miles from home. I wonder if we are taking a big risk by trying to drive more on our MPV prior to any repairs?
  • rollingrolling Posts: 5
    After 2 cylinder misfires in the last month on our 2003 MPV with 83k miles, the vehicle now has all new spark plugs, ignition coils, and a PCV hose (while we were there). For the second time since, I got the CEL 'warmup catalyst efficiency below threshold (Bank 2)'. I got the O2 tests run today and sure enough, the warm-up converter connected to the cylinders that were misfiring is no longer effective. Fortunately, it is the less expensive one(!), and the MPV is now running well again.
  • buzzkbuzzk Posts: 15
    Tonight while buying an IAC valve I looked at AutoZone's MPV coil & it has the same vent that the factory coil has & will therefore be subject to getting water vapor & dirt, etc, into the plug well, **and the same failures as OEM coils***. [AND they are NOT "one-way" vents as someone said - they are just a lot smaller on the top but there is NO valve effect, so everything goes both ways] No wonder so many fairly new coils fail! The tech/salsemen advised plugging the vent w/hi-temp silicone rubber, which should work . I did that w/my original coils [after cleaning both the coils & the spark wells - filthy!] & they worked fine til my after-market coils came in the mail. The salesman thought the factory design was never changed due they'd have to have a massive recall? maybe.. but MPV owners need to understand any coil w/a vent in it is a problem waiting to happen. If folks can't get a vent-less design like I got from e-bay, then I would suggest they consider asking their mechanics to plug the vents w/silicone before installing them. their call, but that's what I did & it worked for me.

    Cheers, BK
  • jipsterjipster Louisville, KentuckyPosts: 5,511
    edited July 2011
    The vented newer coils are not a problem. They were redesigned about 5 years ago. Only the old coil design sucks.. different part #.

    3 of my original 6 OEM coils failed within 5 years. 3 years and no problems with new coils.
  • buzzkbuzzk Posts: 15
    Glad to hear of the improvement, there might still be hope for Mazda, even if they did make the newest Miata less attractive [almost ugly?], but.... if the OEM coils are still vented - as AutoZone's new after-market coil is, I'll stay away.. Any kind of vent in this application is still asking for touble [mainly in the form of water vapor] in my book. I put in the new IAC valve & we'll see how that goes & I'll be looking for a good local price for Denso O2 sensors... or get 'em from the internet..

    Cheers, BK
  • Your P0455 Code is could be from a service bulletin that I located from working on a MPV like yours. The URL is:

    This should fix your problem. If not check fuel cap/seal area, or pressurize the evap system and sniff for leaks.

    Good luck. I can be reached at [email protected]
  • Hawkeyes2: Your P0455 code could be part of a Mazda recall. The harness is to short going to the purge solenoid connector. Click on this URL to see your problem:
    This should take care of your problem.

    [email protected]
  • Just purchased my 2005 MPV about 5 months ago.
    Recently the low beam headlights have started turning off, somtimes they wont come on at all and others they will turn off while driving. The high beams work with no problems.
    Do any one have any advice on where to start looking for the problem or has anyone had this problem?
  • dbdbdbdb Posts: 1
    Did you ever figure out why the headlights were coming on? My 95 is having the same problem.
  • A fix for MPV misfires and coil problems... After several episodes of fouling plugs and/or bad coil packs, usually after rains, I began to look for causes and tried an experiment by leaving the black plastic shroud off when I replaced the plugs and coils. I suspected it was trapping moisture and humidity and forcing it down into the plug wells. Amazingly, my MPV has been misfire free for close to three years now. The longest I had gone previously was 12-15 months...when the van was new! It may just be coincidence but it worked for me!

  • SadiesSadies CAPosts: 2
    Can someone please help me. I went to get a smog. My 2002 mpv did not pass because my check ingine light did not come on while they tested lights. So I went home and changed the bulb myself. It does not come on When I check my lights. Is that normal or do you think its another problem???
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