It depends on how much you will use it and how much you want to spend. Fluke are real nice but if it's going to sit in the toolbox after being used once, . . . I picked up an inexpensive one at Harbor Freight or Walmart and it works just fine. It sounds a tone on continuity.
I used a "Radio Shack" multimeter for several decades until finally thinking last year that it may be inaccurate (in obsessing too much over how much voltage my Roadster battery had) so I went out and bought a Fluke 115. Found that the Radio Shack meter was pretty accurate after all. But happy I now have the Fluke. But for what you need to check for here immediately, find an old flashlight, take out the bulb and use ordinary tape to tape two wires to each contact on the bulb, tape two wires to both ends of the 1.5 volt battery, connect one of the wires from the battery and from the bulb together, and then use the remaining two wire ends coming from the battery and the bulb to check for continuity. Touch the two wires together and if the bulb lights dimly you have a continuity checker you can use to check the pins. If you have an inexpensive battery checker you can do the same thing taping wires to it with a 1.5 volt battery. Important, do not only check for continuity on the two noted pins, but also check to confirm that there is NO continuity on any of the adjacent pins. It is just as easy to have solder overflow on small pins like this wire needed to be connected to, as it is to have a bad solder joint.
Here is the order I found had to do it in, not following completely the above but maybe misunderstanding it somewhat. First, I erroneously thought I could "copy" the numbers I was getting in 'tpms read' into a tire set but that is not possible as the 'read' command inserts commas while the commands that write the numbers use spaces. It took me a while to figure that out. Then after getting zeros in the TPMS or not understanding how to write correctly, here is what worked for me in the order I did it to set both "Summer" and "Winter" tire sets in OVMS, and to upload the "Summer" TPMS numbers in to the Roadster's TPMS: To set a "Summer" tire set in OVMS: tpms set summer 11111111 22222222 33333333 44444444 To write that tire set to the Roadster TPMS sensors: tpms write summer To check to see if the numbers written to "Summer" and to the Roadster TPMS sensors took: tpms list To double check what is currently written to the Roadster TPMS sensors: tpms read To set a "Winter" tire set in OVMS for use later on: tpms set winter 55555555 66666666 77777777 88888888 To check that both "Summer" and "Winter" tire sets are written to OVMS: tpms list I think I have this right. In any event, the above worked for me and I am ecstatic that I can now set the TPMS sensors in my Roadster without having to go to the SC. Thanks again to everyone who worked on this project!
The only one I would add is: tpms read summer To read the current tyre IDs from the car and store them as set 'summer'.
I think a continuity check is required to narrow this down. I suggest you check all the way from the end of the DIAG cable (that plugs into the car) to the expansion connector. A Fluke is the gold standard; If you want something to last a couple of decades that is probably it, but way overkill for what is usually required. Something simple you pickup at the local hardware / auto store is probably sufficient - although I would get a battery powered one (rather than an analog one with a dial).
@markwj FastTech says "Discontinued" is that just how they say "Out of Stock / Backordered" or is it being modified?
The status should be 'out of stock'. No modifications necessary (that i know of). They unexpectedly sold out of their initial stock within a few days, and are currently re-stocking. This should be back in stock at the weekend, or early next week (depending on courier shipping and customs; both of which are very unpredictable these COVID-19 days).
Picked up a multimeter (a Fluke 101) and tested across the correct pins and got continuity then checked adjacent pins on both sides and confirmed no continuity so it seems the jumper is fine. So what else is left to check? Could it be that my TPMS was upgraded from the Baolong system? Is there a way to check without dismounting the tire?
I can't believe that I've been away from this forum for so long. Fortunately, I heard about this TPMS upgrade on the OVMS mailing list. I'm looking at the "Discontinued" status on FastTech and have registered my email address for an update when they're available again. I'm been looking forward to a summer+winter TPMS system like this for ages, and almost started on a solution myself. I'm much happier that Mark got it working!
Welcome back @S-2000 Roadster! Since we last heard from you, OVMS can now indeed read/write TPMS (for some; me, not so much), 2.5 Base models are now valued at $100K (at least according to Donald Osborne) and #2500 has been listed for $1MM (originally $1.5MM) @markwj / @JohnGarziglia / @Nvbob would love your thoughts on this thx ^^
i would think it unlikely that you have different TPMS hardware as that would most likely need firmware changes to work
ok, my thoughts 1. Car can read temps from sensors. - yes 2. OVMS reads temps from sensors - yes 3. OVMS TPMS "read" command does NOT return sensor id's (ignition on) - yes Possible solution (?) - go to tire shop and have them use their TPMS scan tool to read the sensor id's and enter them manually for a "tyre set" (create your own name for the set - i.e. summer, winter, mine, default, etc) I did an internet search to see if a TPMS scan tool would reveal the manufacturer of the sensor along with the ID but was unable to find anything. I also tried to find if the sensor ID would help determine the manufacturer (similar to a MAC address on a computer network card) but was unable to find anything, again. I can only "assume" from #1 & #2 above, you have OEM (Baolong) sensors because they are working with the OEM TPMS system. Your thoughts?
@Nvbob - I just went through service records and it appears all four sensors/valves were replaced in 2017 along with a rear Baolong antenna (see service record excerpt below). If the antenna is Baolong, all the sensors should be as well, correct? Is it possible I have a bad PCB? If so, no clue what else to do at this point but perhaps I'll just undo everything and reseat the daughter board. @markwj anything else left to try?
I disassembled everything, reassembled it and restarted the module. Ran the commands shown below and you can see the results: "tpms read" still throwing the same error msg Out of curiosity, does "tpms status" read from the new TPMS module or is that simply a straight read from the CAN bus? If the prior, does the fact that it's reading pressures and temps mean my module is working as expected? I'm at a loss here I'm afraid. Best case, I've still got something configured wrong that can be addressed easily. Worst case, this was a $25 USD OVMS ornament.
Please eMail me at mark (at) openvehicles (dot) com. Please send me the output of the 'module summary' command on your module (type that in the shell/messages window). We'll work through this step by step. I'll need access to the car remotely, so best to arrange on eMail. Regards, Mark.
I'm glad @markwj is picking this up. Let's see what you both find. Dumb question - could your JdeMo modification have any effect on this TPMS issue?
I wouldn't have thought so since both systems are independently functioning as expected... but you never know. Let's see what Mark's diagnosis turns up. I'm still curious about this as well. Thoughts?