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Troubleshooting a TPMS Fault

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by brick, Jun 22, 2012.

  1. brick

    brick Active Member

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    A few years ago the other '07 had a bad encounter with a tire shop, and left without the TPMS system working. I went around with them for a while and ultimately gave up, unable to deal with an obstinate shop manager and not wanting to shell out who knows how much cash to get it fixed by Toyota. We have tire gauges and we know how to use them.

    Today I decided to take a crack at diagnosing the issue myself using an AutoEnginuity scanner with extended coverage for Toyota. (Don't worry, I didn't sink that much cash on a tool **just** for this project.) The original symptom is that the TPMS light indicates a fault (flashes for a minute and then goes solid) and TPMS initialization doesn't do anything. When I scan for DTCs I see the following:

    C2121 - Transmitter ID1 Not Received
    C2122 - Transmitter ID2 Not Received
    C2123 - Transmitter ID3 Not Received
    C3e3f - Unknown Trouble Code Description

    Those trouble codes seem to point to three bad sensors. The strange thing is that I see sensor data from supposedly bad transmitters. For example, I see similar temperatures and pressures in both ID1 and ID4. I also see battery voltage listed as "Over 1.6V" for all four sensors. It's possible that the voltage is a red herring, but the pressure and temperature in #1 must be real. Yes, the 12V battery is just fine.

    I'm not done troubleshooting, but I'm curious if anyone has any suggestions. Surely I'm not the first person around here to take a shot at a problem like this?
     
    #1 brick, Jun 22, 2012
  2. wick1ert

    wick1ert Senior Member

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    Were you able to clear those codes? An "ID Not Received" code is unusual for a malfunctioning sensor, as I believe there's a different error that displays in those instances. I thought ID not received was for when someone was trying to update the IDs and it didn't take properly. You might be OK if you can get the codes cleared. Unfortunately, Upstate NY to here is a long trek or I'd offer to hook it up and do it for you.

    You may be able to disconnect the 12V to clear the codes, and see if they reappear again.
     
    #2 wick1ert, Jun 23, 2012
  3. brick

    brick Active Member

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    Thanks for the response and the offer. I would take you up on it if we were a bit more local.

    You know what's interesting, I think that the description that comes up in AE was wrong. According to Alldata, C212[x] codes are "No signal from transmitter ID[x] in main mode." If it were really "ID not received" it should have set a C218[x] codes. I guess I need to double check these things since I'm not using Techstream. That makes more sense if the sensors are malfunctioning. As I understand it, those codes don't clear until the ECU hears the sensors transmitting. Plus the car has been like this for years, and it has been through at least a couple of 12V disconnects for other work.

    Last night I got it in my head to test by registering the sensors from the other car (with working TPMS) to the malfunctioning car. Unfortunately I didn't get very far. I started the registration process and the scanner came up with a "test failed" error before asking me for IDs. There is a TSB on a similar problem when registering with Techstream (T-SB-0084-09) but the procedure didn't change the situation for me. It throws an error when I try to enter "signal check" as well. Thing is, that could just as easily be an issue with my aftermarket scan tool and software as with the car.
     
    #3 brick, Jun 23, 2012
  4. wick1ert

    wick1ert Senior Member

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    A quick google also returned Toyota document that shows those DTCs are no signal from transmitter. This could either be a bad transmitter (possible if the shop jacked them up) or an issue with the registering of the transmitters in the ECU.

    I'm thinking, without someone nearby with TechStream, you're stuck dealing with a dealership if you really want to fix the problem. TPMS isn't an essential component, as you know, and your car will operate just fine without working sensors. The dealer will charge at least $100 per sensor, plus labor. You can get sensors cheap on ebay, but you'll still need to get them registered with either an ATEQ tool or cable for TechStream. Alternatively, you can try to find someone that sells the EZ Sensor, which can be programmed to match your existing TPMS IDs. I've only heard of one person on here having success in finding a retailer of them, though.

    Otherwise, if you have a laptop with Windows XP, I can loan you a cable (just pay me shipping) that works with TechStream and you can investigate things on your own. This particular cable does work, as I've used it a couple times to update the TPMS when I swapped between winter/summer wheels, but only has Windows XP drivers. You can usually find a copy of TechStream online to download, and can usually use it in evaluation version or pay for a 2 day subscription if you wish. Just let me know.
     
    #4 wick1ert, Jun 23, 2012
  5. brick

    brick Active Member

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    Thanks for the offer! I'll keep it in mind.
     
    #5 brick, Jun 23, 2012
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