Source
r/lotus•
SomeoneElse899

Has anyone had issues connecting with their S2 Elise through ODBII?

I've owned an Elise for several years now and have a couple OBDII readers I've connected to the car with. Now that the winter is over for me I've been working on getting the car out and back on the road. When I started the car up, a check engine light eventually came on but I was unable to scan my car, none of my readers could connect to it.

Has anyone had this issue? I've seen a few posts on LotusTalk on the topic, but I haven't found a solution yet.

Edit: if anyone finds this looking for a solution, the solder joints on the instrument cluster cracked, and fried (Im assuming its responsible) the k-line chip on the ECU. The chip is ST Microelectronics L9613.

Posted Mar 20, 2022, 2:59 PM UTC · edited

921
Eric1180•

Hmm I run a Bluetooth OBD scanner connected to my aftermarket radio to pull engine stats. Its stay in there 24/7. I havent had an issues with mine. Are you using the right protocal to connect. I can check what it is if you want.

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odc100•

I’m not OP but I’d love to know the protocol, thank you!

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SomeoneElse899OP•

I've found in my research that the protocol is ISO 9141-2, which also seems to be called K-line.

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SomeoneElse899OP•

Are you using the right protocal to connect.

Who knows. I have the Torque app and for the most part it seems automatic. I've used it plenty of times before, except now it does not work.

I'm starting to think some mouse or some animal got into something electrical. The CEL is now intermittent; it will be on for 10 second, then off for a bit, then back on. My gas gauge is bouncing all over the place too. It was almost full when I pulled it into the garage, and now its showing empty.

1
archaeopterxyz•

Ugh, Torque! I used it for a few years, then it started getting really buggy so I swapped for a physical scanner. Less convenient, but zero issues connecting. Much happier in the end.

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SomeoneElse899OP•

I havent had a problem with it up until now. Turns out I had a blown k-line chip on my ECU, so noting wouldve worked. I had a cracked solder joint in my gauge cluster which must've fried it. Solder joint is fixed, but now I need to wait for delivery on the IC.

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neildmaster•

Check the fuse on the OBDII port. Sometimes they go bad and the scanner won't connect.

3
SomeoneElse899OP•

The bluetooth adapter I have is getting power, and I can connect to it. I'm thinking theres something electrically wrong with it. (from my other comment) The CEL is now intermittent; it will be on for 10 second, then off for a bit, then back on. My gas gauge is bouncing all over the place too. It was almost full when I pulled it into the garage, and now its showing empty.

I'm going to hook up a battery I know is good, hopefully that's my issue. I've seen weak batteries do some odd things to auto electronics.

1
juban97•

This happened to me, it turned out the K-line chip on my ECU was fried. I have pictures, it was pretty easy to see what went wrong. Mine is an 05

3
SomeoneElse899OP•

How did you find out that was your problem? How did you fix the issue?

I'm having all sorts of weird things going on. My check engine light will turn off and on. The door chime doesn't work all the time when the door is open. My fuel gauge will be full, then empty, then full.

2
juban97•

Well I’m not sure about the intermittent dash issues, I did not experience those problems. For me, proven OBD readers just stopped working one day. Nothing would connect, even though the ECU was still functioning and the car was turning over and running. I had to remove the ECU and open it up. The K-Line chip was clearly burnt out, it had a large melted circle of plastic on the top face. This chip can be replaced, I believe it is still manufactured and sold on websites like Digikey

3
SomeoneElse899OP•

Just opened the ECU up, and sure enough, that chip is a little burnt. Digikey and Mouser don't have any in stock, and the mfr. lead time is 52 weeks, ouch.

When you fixed it, did the issue come back? Any idea what causes it to blow?

2
juban97•

Well I’m glad you located the problem at least! Though that sucks about lead times, I guess I’m not surprised given the global micro chip shortage.

The problem did not come back for me. This thread on lotus talk discusses the same problem and they say it’s either a short or plugging in the wrong OBD2 reader that can cause it

https://www.lotustalk.com/threads/obd-reader-wont-communicate-w-reflashed-ecu.88207/

I don’t think the problem came back for the guy in this thread either

3
PhillLacio•

Is your tach needle working? There's a common issue with these cars where the dash loses signal because of a bad connector (easiest tell is if the tach reads 0 while the car is on). If that happens, OBD2 no longer works.

2
SomeoneElse899OP•

It did, its not anymore. The speedo and tach are intermittent (that can't be a good thing), so speedo come on for a second or two, and then stop. I have the instrument cluster off and the contacts look fine. Do you think I should split the cluster open?

1
PhillLacio•

If it's still intermittent, you are still experiencing the connector issue. Head to the forums and look up how to resolve it, once that's fixed your OBD2 should come back. The trend I noticed is that whenever the dash is intermittent, so is the OBD2 connection.

2
SomeoneElse899OP•

I took the cluster apart and found a cracked solder connection on the OBD2 connector. Soldered it back up and.... no dice.

1
PhillLacio•

Bust out the multimeter and see if there's voltage to that pin. You may have soldered it back up but there could still be another issue.

As for the cluster thing, you'll need to remediate that as well for OBD2 to work properly. Mine was intermittent as well as that would cause the OBD2 connection to drop.

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[deleted]•

[deleted]

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