lexia cable - what is it for?
  • Register
  • Help
Results 1 to 17 of 17
Like Tree1Likes
  • 1 Post By SLC206

Thread: lexia cable - what is it for?

  1. #1
    1000+ Posts gerry freed's Avatar
    Join Date
    Jun 2003
    Location
    Lauderdale, Tasmania
    Posts
    2,834

    Default lexia cable - what is it for?

    When I bought my Lexia3 à la Chinoise it came with all the cables I need. In addition there is a cable set with the OBD2 plug at one end and two cables attached. One breaks out to two large crocodile clips like battery charger clips and the other cable has a plug with two flat pins.
    What is it for?

    Advertisement
    Think Global - Ride on Spheres

  2. #2
    Fellow Frogger!
    Join Date
    Oct 2010
    Location
    Melbourne
    Posts
    709

    Default

    Great question.
    206 GTi 180 - Cat Cams, Remapped Group N ECU, AST Camber Tops & Coilovers, -2deg fixed camber hubs by Frogstomp Racing, 24mm Torsion Bars, AP Racing brakes, Yokohama A050, PeugeotSport Baffled Sump, Powerflex Engine Mounts & Bushings, Setrab Oil cooler, Quaife diff, Velo seats.

    Sandown - 1:31.5
    Winton - 1:45.6
    Phillip Island - 1:58.4
    Nürburgring - 10:23.ish (Fiesta ST)

    Previously, 2x 504 Wagon, 505 Wagon, 505 STi, 405.

  3. #3
    1000+ Posts
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    6,627

    Default

    It's a memory saver. You can preserve the BSI settings with the battery removed by applying 12v to an OBD pin. (16 is battery power). Obviously connect the second source before removing.

    It also infrequently can work the other way, for small loads like instrumentation, though there may be a diode inserted.
    Last edited by seasink; 21st July 2017 at 02:39 PM.

  4. #4
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    15,610

    Default

    It also infrequently can work the other way, for small loads like instrumentation, though there may be a diode inserted.
    Where does the 12v+ come from?, not from the computer usb or serial port that is for sure.
    Mutual Respect is Contagious


  5. #5
    1000+ Posts
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    6,627

    Default

    There is a 12v OBD pin, connected to the computer power source. Normally the source is from the car battery, but either way will keep the computer alive.

    The Lexia/Diagbox is converting an asynchronous signal, a bit over 10 kbits/s if my memory is correct. It isn't a world away from serial RS-232 on a computer.

  6. #6
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    15,610

    Default

    Quote Originally Posted by seasink View Post
    There is a 12v OBD pin, connected to the computer power source. Normally the source is from the car battery, but either way will keep the computer alive.

    The Lexia/Diagbox is converting an asynchronous signal, a bit over 10 kbits/s if my memory is correct. It isn't a world away from serial RS-232 on a computer.
    Sure, But how does the lexia device connect to the Pc ?

    And get the power the "for small loads like instrumentation" which presumably back feeds the Obd port?

    The Pc connection is likely either serial (no power available) or Usb (5v at a few hundred mA), There is no 12v available from either USB or serial ports.

    Unless computers have recently developed custom ports for interfacing "lexia" devices.
    Mutual Respect is Contagious


  7. #7
    Fellow Frogger!
    Join Date
    Oct 2010
    Location
    Melbourne
    Posts
    709

    Default

    The way I understand it, the extra cable being spoken of is to retain the BSI and or ECU settings in volatile memory whilst the main car battery is disconnected. It's simply a 12v supply, connected via the OBD port. In this case the 12V will be supplied by an auxiliary battery connected by croc clips.

    Alternatively, the cable could be used to supply an instrument. In this case the 12V comes from the car, which is in fully (mostly) working order.
    206 GTi 180 - Cat Cams, Remapped Group N ECU, AST Camber Tops & Coilovers, -2deg fixed camber hubs by Frogstomp Racing, 24mm Torsion Bars, AP Racing brakes, Yokohama A050, PeugeotSport Baffled Sump, Powerflex Engine Mounts & Bushings, Setrab Oil cooler, Quaife diff, Velo seats.

    Sandown - 1:31.5
    Winton - 1:45.6
    Phillip Island - 1:58.4
    Nürburgring - 10:23.ish (Fiesta ST)

    Previously, 2x 504 Wagon, 505 Wagon, 505 STi, 405.

  8. #8
    1000+ Posts
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    6,627

    Default

    There's a mix-up here. I'm talking about Gerry's mystery cable. There isn't a computer attached.

    The Lexia/Diagbox cable has a box of electronics on a card inserted into it to convert the OBD serial signal to USB at the computer.

    Edit: Speaksgeek puts it better.

  9. #9
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    15,610

    Default

    Quote Originally Posted by seasink View Post
    There's a mix-up here. I'm talking about Gerry's mystery cable. There isn't a computer attached.

    The Lexia/Diagbox cable has a box of electronics on a card inserted into it to convert the OBD serial signal to USB at the computer.

    Edit: Speaksgeek puts it better.
    OK , so I wrongly assumed the "mystery cable" was part of the Lexia cable.

    I now see I am in error.
    Mutual Respect is Contagious


  10. #10
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    15,610

    Default

    Quote Originally Posted by seasink View Post
    There's a mix-up here. I'm talking about Gerry's mystery cable. There isn't a computer attached.

    The Lexia/Diagbox cable has a box of electronics on a card inserted into it to convert the OBD serial signal to USB at the computer.

    Edit: Speaksgeek puts it better.
    OK , so I wrongly assumed the "mystery cable" was part of the Lexia cable.

    I now see I am in error.
    Mutual Respect is Contagious


  11. #11
    1000+ Posts gerry freed's Avatar
    Join Date
    Jun 2003
    Location
    Lauderdale, Tasmania
    Posts
    2,834

    Default

    Name:  s-l64.jpg
Views: 95
Size:  2.1 KB
    Here is a photo of the cable concerned. Nothing to do with the Lexia interface
    Think Global - Ride on Spheres

  12. #12
    1000+ Posts
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    6,627

    Default

    When I put on my magnifying specs, I see a memory saver. People often use them with a 12v jump starter, or other battery.

    No Lexia connection. If you want to verify it, put it on a battery, and see if pin 16 is +12v.

    These may be of interest-
    http://pinoutguide.com/CarElectronics/peugeot_obd_ii_diag_pinout.shtml

    http://pinoutguide.com/CarElectronic...2_pinout.shtml
    Last edited by seasink; 21st July 2017 at 08:10 PM.

  13. #13
    1000+ Posts gerry freed's Avatar
    Join Date
    Jun 2003
    Location
    Lauderdale, Tasmania
    Posts
    2,834

    Default

    Quote Originally Posted by seasink View Post
    When I put on my magnifying specs, I see a memory saver. People often use them with a 12v jump starter, or other battery.

    No Lexia connection. If you want to verify it, put it on a battery, and see if pin 16 is +12v.

    These may be of interest- Peugeot OBD II diagnostic connector pinout diagram @ pinoutguide.com
    Citroen OBD-2 diagnostic pinout diagram @ pinoutguide.com
    Thanks, that must be the logical answer but what is the 2 pin connector for? It is not connected to the +12
    Think Global - Ride on Spheres

  14. #14
    1000+ Posts
    Join Date
    Jun 2013
    Location
    Sydney
    Posts
    6,627

    Default

    Neither of the pins goes to OBD2 battery or chassis ground? My guess would be to suit a solar battery charger (camping etc) to trickle charge via OBD.

  15. #15
    sans witticism SLC206's Avatar
    Join Date
    Sep 2003
    Location
    North Parramatta
    Posts
    3,758

    Default

    I always assumed the two pin connector was for earlier cars (306, 405, 205, BX) that had an ECU diagnostic plug for the ECU and sometimes for the ABS - which was a two pin connector.

    You could use PP2000 to interrogate the ECU.

    This was how the previous "official" test tool - the TAD 4-99 - worked.
    Last edited by SLC206; 23rd July 2017 at 04:47 PM.
    hypermiler likes this.
    Regards,

    Simon

    2014 208 GTi 2011 DS3 DSport
    ----
    2007 207 GTi 2004 206 GTi180 2000 206 GTi 1995 306 XT

    www.peugeotclub.asn.au

  16. #16
    1000+ Posts Ken W's Avatar
    Join Date
    Sep 2002
    Location
    North Brisbane
    Posts
    1,427

    Default

    Yes, I can confirm it is for the early ECUs used in the BX, 306 and 405 cars that have the 2 pin green connector with K and L leads.

    Cheers, Ken

  17. #17
    1000+ Posts gerry freed's Avatar
    Join Date
    Jun 2003
    Location
    Lauderdale, Tasmania
    Posts
    2,834

    Default

    Thanks for your help. I will consign it to the "will need it someday" shelf.
    Think Global - Ride on Spheres

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •