97 F355 Spider ECU Issue/Smog Issue | Page 5 | FerrariChat
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97 F355 Spider ECU Issue/Smog Issue

Discussion in '348/355' started by Loser, Jun 10, 2008.

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  1. jm3

    jm3 F1 Rookie

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    #101 jm3, Jul 28, 2008
    I sent you the MAF on UPS today. Fedex on your account was beyond useless. They wouldn't take it the same day on your account, unless it was "express" . So I told Fedex it was "express" and then when the guy showed up (I have a Fedex account), I was required to choose Next day, 2nd day, or 3 day to travel 3 hours by car.

    I then recalled why I ship very little by Fedex, and sent it to you on UPS guaranteed for $6.32.

    You will have it tomorrow, and you will be getting an emailed tracking number in the middle of the night.


    Jay
     
  2. Loser

    Loser Formula Junior

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    #102 Loser, Jul 29, 2008
    Hmmm. Sorry about that. I've never really had any problems with FedEx. I'll send you the money with the MAF after I try it out which will hopefully be tomorrow. I almost have all the codes cleared. I am only showing the MAF code, P1691 which is due to the CEL being disconnected, and P1445 which I still need to figure out. I have until Thursday to clear everything and pass the smog or I will be in line for a few hours at DMV again begging for another extension.
     
  3. Loser

    Loser Formula Junior

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    #103 Loser, Jul 30, 2008
    Hi Jay,

    Your MAF was Bosch part # 0 280 217 803 instead of part # 0 280 217 800 and it has a different connector. I am assuming that this will not work. Any feedback?
     
  4. spider348

    spider348 Formula 3

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    #104 spider348, Jul 31, 2008
    If the MAF you received is incorrect I have the correct Bosch MAF recently changed in my 355. I am trying to rectify a very minor on throttle lag issue that I was convinced was MAF related. No change with the newly installed MAF so my old MAF should function for you to test.
     
  5. Loser

    Loser Formula Junior

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    #105 Loser, Jul 31, 2008
    Thanks spider348, but I have another one coming already.
     
  6. Loser

    Loser Formula Junior

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    #106 Loser, Jul 31, 2008
    P1691 is now fixed. The previous owner had removed the CEL bulb and changed the location of the gels in the instrument panel so the the CEL gel was over the battery light. After moving the gels back to the proper locations, I found that I am missing the gels for the battery and the slow down indicators. I ordered a gel from FerrParts and am waiting for it to arrive.

    So now I am left with an intermittent P1445. I see a P1448 today, but it is possible that when I switched the wires for the two temperature ECUs to debug the issue, that I didn't properly switch them back. Does anyone know which ECU on the passenger side rear goes to which thermocouple?
     
  7. f355spider

    f355spider F1 World Champ
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    May 29, 2001
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    #107 f355spider, Jul 31, 2008
    Last edited: Jul 31, 2008
    How about simply switching the plugs from either the thermocouples or the power/data plug (not both, obviously) and see if it corrects the problem?

    I could see where mixing the two up would trip the P1448. The motronic would think the exhaust valve is always open since the thermocouple would be constantly hot , even when the valve is closed (since the thermocouple is reading the cat instead)...which would likely cause a P1448 code. P1445 maybe if it is supposed to be reading the catalyst temp, but is instead reading the valve...and if the valve is closed, then the thermocouple is reading much colder than the Motronic thinks the catalyst should be?

    I would check my car for you, but it is in the shop right now, and not handy...I would think there must be identifying marks on the two power/data plugs to the right catalyst ECU and exhaust valve ECU so you can tell them apart.
     
  8. Loser

    Loser Formula Junior

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    #108 Loser, Jul 31, 2008
    Both ECUs look identical except one is horizontally mounted and the other is vertically mounted right next to it. Either plug fits in either ECU. I can tell which plug is which by following it to the source, but I can't tell which ECU is which.
     
  9. jm3

    jm3 F1 Rookie

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    #109 jm3, Jul 31, 2008
    WOW....... I'm not so sure that was accidental.

    You must be ready for detective school.

    Jay

    ps. Sorry about misreading the teeny numbers on the hfm
     
  10. f355spider

    f355spider F1 World Champ
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    #110 f355spider, Jul 31, 2008
    The ECU's are identical, it doesn't matter which goes where. I have mine swapped presently (between right and center cats) to check an intermittent "slow down" light. I did not physically move the ECU's just moved the two plugs from one ECU, to the other ECU. I am thinking if you only swapped the thermocouples, for example, it would give you the two codes you are now seeing....because the readings are coming from the wrong places, so the Motronic is expecting different temperatures than it is seeing.
     
  11. Loser

    Loser Formula Junior

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    #111 Loser, Jul 31, 2008
    Yes, I only switched the thermocouples. I thought I switched them back, but maybe not. It's hard to see around all of the hoses that are in the way.
     
  12. Loser

    Loser Formula Junior

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    #112 Loser, Aug 1, 2008
    Currently, my cat thermocouple goes to the vertically mounted ECU closer to the inside of the car. The bypass thermocouple goes to the horizontally mounted ECU closer to the outside of the car. Can someone confirm if this is the correct configuration as it comes from the factory?
     
  13. Loser

    Loser Formula Junior

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    #113 Loser, Aug 1, 2008
    Nevermind. I switched just the thermocouple cables and got a slow down light at 4000RPM. I switched them back, cleared the codes, and am only seeing the MAF code now. It seems the P1445 and P1448 are intermittent. I wonder if they are related to a bad MAF? I have another MAF coming on Monday.
     
  14. f355spider

    f355spider F1 World Champ
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    #114 f355spider, Aug 1, 2008
    Tom, it is entirely possible you either have a bad connection to the cat ECU's, or (more likely) simply a bad cat ECU. The early ones are filled with black epoxy, later, upgraded ones are filled with green epoxy. Both have a black plastic housing. The black epoxy ones are known to develop cracks and allow water to seep in causing shorts and intermittent malfunctions. Some have successfully sealed them up with silicone RTV, but probably best to replace suspection ones. They are $329 each from Ricambi.
     
  15. Loser

    Loser Formula Junior

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    #115 Loser, Aug 1, 2008
  16. Loser

    Loser Formula Junior

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    #116 Loser, Aug 2, 2008
    I just replaced my MAF with another MAF and I am still getting P0102 Mass or Volume Air Flow Circuit Low Input. Any ideas? Should I measure the four pins in the connector? If so, what should I see on them?
     
  17. Loser

    Loser Formula Junior

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    #117 Loser, Aug 2, 2008
    I disconnected the MAF and measured the voltages on the four pins of the cable without the MAF connected and with the car running. One pin was 14V and the other three were 0V.
     
  18. eric355

    eric355 Formula 3
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    #118 eric355, Aug 3, 2008
    On the 4 pins you have:
    - +12V
    - power ground
    - signal ground
    - MAF signal
    That's normal you measure 3 pins at 0V when looking Motronic side

    Can you measure these same pins wrt to ground with the connector connected and the car running (removing the protection boot at the rear of the connector)
    Also if you clear the DTC, does it comme back if you stay at idle or when the engine needs more air?
     
  19. spider348

    spider348 Formula 3

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    #119 spider348, Aug 3, 2008
    I tested my MAF as Eric detailed. Peeled back the rubber boot exposing the back of the connector. I back probed with my volt meter. I read 0 at 2 wires(1 is ground). 12~14v at another. With the car running I read 1.3v~2.5v depending on throttle opening. At idle a pretty steady 1.4v. Apply throttle and the voltage increases.
     
  20. Loser

    Loser Formula Junior

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    #120 Loser, Aug 3, 2008
    Last edited: Aug 3, 2008
    I measure 14V steady on the red wire, 0V on the black wire, 0v on the red/white wire, and 1.4V on the red/black wire. Increasing RPMs a little changed the 1.4V to about 1.8V. Would an airflow issue cause a P0103 fault?
    When I clear the DTC, I have to drive for about 15 minutes before it comes back. I checked both air boxes and the filters are fine.
     
  21. eric355

    eric355 Formula 3
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    #121 eric355, Aug 4, 2008
    Identical problems with 2 different MAF, I would suggest that you recheck the harness for intermitent failure. Indeed, a temporary short of the MAF signal with the +12V or a temporary loss of the signal groung can lead to a MAF signal value above the limits expected by the Motronic. If it is repeated it could set a P0103 DTC (too high MAF signal).
    I have checked some values on my car. With the connector disconnected, the car off, and measuring Motronic side with a good ohmmeter, I got a very solid ground for the 2 ground wires (less than 0.1 ohm with a ground reference taken on the starter), 11 kohm for the MAF signal and more than 200 kohm for +12V. Try to repeat these measurements while shaking the harness as far as you can and look for abnormal variations.

    BTW, in the frame of a project I have in mind, I took the car last sunday and recorded the MAF signal value while driving. I was very surprised that it exceeded +5V at around 240 g/s. I was expecting less than 4.5V. In fact the Motronic computes the mass air flow from the differential voltage between the MAF signal and the signal ground. Unfortunately I didn't record the signal ground to see if the difference is always less than 5V, but with the good ground I checked tonight I doubt the voltage on this pin can vary a lot. I will do another run recording both voltages at the same time to conclude. If you have access to a datalogger, recording the voltage on the 4 pins of the MAF could be an elegant solution to catch an intermitent problem ... if any. Just a thought ...
     
  22. Loser

    Loser Formula Junior

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    #122 Loser, Aug 5, 2008
    Hi Eric,

    I am getting the same readings as you on the Motronic side. I can graph the MAF data using my OBDII ScanXL software, but I don't have a way to datalog the actual voltage unless it is available via a PID in the OBDII data. I'll have to check that.

    The MAF I bought is a used MAF off of a parts car, so it may also be bad. I also purchased the instrument panel indicator light assembly since the previous owner of my car had cut the indicator gels and moved them around to override the CEL functionality due to his removal of the catalytic converters. That took me a while to debug, but in the end, I needed a new gel strip. They sent me the entire assembly from the same parts car. While removing the gel strip from the parts car indicator light assembly, I noticed that the CEL bulb was missing. So it is very possible that the parts car had a bad MAF as well and the owner would not have known it since the CEL bulb was missing. Anyway, I now have a brand new MAF on order to arrive tomorrow.
     
  23. Loser

    Loser Formula Junior

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    #123 Loser, Aug 8, 2008
    I finally received my brand new Bosch MAF. I installed it, reset the computer, idled the car for 10 minutes, and went for a drive. Less than 10 minutes into the drive, I see "P0102 Mass or Volume Air Flow Circuit Low Input." I cleaned the contacts on the connector and even distorted them into a slight oval shape to make sure they had good contact. All signals seem to be fine. I am at a loss on what to do next. I went to the DMV to try to get another extension to the smog test requirement and they said no. So as of midnight tonight, I can no longer legally drive my car :-(.
     
  24. Loser

    Loser Formula Junior

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    #124 Loser, Aug 10, 2008
    Last edited by a moderator: Sep 7, 2017
  25. Loser

    Loser Formula Junior

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    #125 Loser, Aug 10, 2008
    Took the car for a 1.5 hour drive. After about 45 minutes, I saw codes 1124 (Long Term Fuel Trim Additive Air) and 1126 (Long Term Fuel Trim Additive Air (Bank 2)) Appear. Prior to the drive, the Oxygen Sensor Monitor, Catalyst Monitor, and Secondary Air System Monitor tests were still pending. At the end of the drive (<5 minutes before I returned home), the CEL came on as the Oxygen Sensor Monitor test completed. The other two tests are still pending.
     
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