We went to NC to visit our daughter and grand kids. It was a great trip in a great car. We had two strange happenings. In both cases right after a fuel stop and back at highway speed, the dash lit up like a Christmas tree, lost CC and PS. never went into limp mode. Car would run fine at high speed but the dash was lit up. I had my ELM plugged into the OBDII port, watching the coolant temp. During the event the OBDII stopped talking to the ELM. I had remembered to bring my iSOFT code reader so we stopped at a rest stop and started checking codes, CATS, Low brake fluid, TPMS and about a dozen others. I reset them all and remembered I had just filled the tank. Although there was no mention of an Evap problem or Check Gas Cap, I cranked the fuel cap three or four times just to ensure it was sealed tight. Car ran fine through that tank of fuel and did the same thing on the next fill up. After that every time I refueled, I would crank the fuel cap four to five times. Never had another problem the rest of the trip. I am guessing the fuel cap seal may be old and need to be replaced. Any thoughts from you guys?

 

These symptoms point to a battery issue (insufficient voltage to various modules)...your OBDII reader may be the culprit, or, if the battery is original, it may be nearing the end of its life (and the fact that the car starts reliably is no indicator of the above).

 

My first thought is it is related to the OBDII reader being plugged in.

 

Thanks for the input, all suggestions are welcomed and appreciated.

SOV, the car was doing 80 at the time of both occurrences and the ELM indicated 14.1 volts.
Tervuren, the ELM was plugged in for the entire trip with only two occurrences, each after refueling and none after I started cranking the fuel cap down tighter.

Not saying I disagree with either suggestion, I will certainly keep them in mind as I work through this. My daughter and family followed us back home, so I haven't had a whole lot of time to check it out. First check will be to leave the fuel cap loose and take a ride to see if the symptoms will repeat.

 

A weakening battery could well be the cause. I would certainly check and rule it out if possible. The 14.1v when running would be the charging voltage. It does not necessarily mean that the battery is good especially if you are getting a host of unrelated "problems". If it is just a battery, that would be the cheapest fix

Bluetooth OBD reader have been known to throw up problems so certainly keep that in mind.

Fuel filler caps do fail and don't maintain pressure in the system. Worth a check and no harm in changing on a car that is 12 years old - but would it cause all those other problems (CATS, Low brake fluid, TPMS have no connection to the fuel system)?

 

The orig. owner of my XKR had fuel cap replaced twice by the dealer in the first 2 years due to being defective.

 

Hi Neil, I do concur but I've only seen it happen on start up or at idle. I would think the 14 volts from the charging system should prevent these type of fake events. I got tied up with family yesterday but will get out and try the loose fuel cap today. I'll let you know what happens.

 

I had a weirdness about a week ago;
Driving home from shopping with the wife at night.... I started the car up and immediately noticed the battery voltage was at 12.7, so I gave a little rev.......... still 12.7 volts. ****! I hurriedly drove home, watching the voltage the entire time....... it did drop down to 12.6 just before I pulled into the garage, about 15 mile drive. It WAS night and I had the lights on, but everything else off but the TSD every once in awhile to check volts (Torque app on TSD).
I shut the engine off, then restarted it and............ 14.2 volts.
Dunno, man. Torque I'd imagine was operating correctly, as the coolant temp and vacuum changed as expected.
Anyway, it's not happened again since. One of those strange things that happens once in awhile.

 

Maybe it was just the BMS going through its discharge cycle.

 

I didn't think of that. May be.

 

1. and a route map.

2. The toys stay in the tool bag unless a fault develops. I don't go around permanently hooked up to a heart monitor so my cars don't either.

Graham

 

Hi Graham, wife takes pictures, not me. I'll see what she has on the phone. I'll see about a route map in the morning.

 

I finally got some time to do some checking this morning. First I loosened the fuel cap and went for a drive, no lights came on the dash, not even the CEL. Not sure what to think about that. When I got home, I locked the car and opened the trunk then went inside for about an hour. When I came back, the trunk lights had gone off as they are supposed to. I checked the static battery voltage and found 12.73v. Could still have a battery problem but it's looking less likely. I reseated the fuel cap and will drive around town and see if the problem returns.

 

I've had the dash light up on my XK while cruzing along...
Sure enough, pulled the Bluetooth OBDC reader and never saw the issue again.

 

Eyes on the road! EYES ON THE ROAD!!!!!

 

Hey! I was keeping it under a hundred! (I think.....maybe....)............S'all cool

 

My '07 XKR went through a phase of stalling. I eventually realised that it coincided with me using my OBD dongle.

The last time it happened the car was totally dead and only disconnecting the battery for a few seconds brought it back to life. At that point I stopped using it and bought a new one!

 

Cleaver, you could be right. After I run around for a week or so, I'll plug the dongle back in and see if the problem returns.