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St. Louis, MO
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Discussion Starter · #21 ·
Uh oh - Limp mode. Added some Octane boost (just used the STP Stuff), and then topped off with more 93 octane about 2 gallons (tank was full). Drove for about 40 minutes and car seemed to run better and knock seemed to go away.. Then stopped for about 10 mins to pick up lunch...came out started car and all was good...pulled out to busy street and went into limp mode - no throttle at all...just idle. JB4 was disconnected and would not connect. Messed with the JB4 under the hood a bit and it connected but still full limp mode - no throttle whatsoever. Then I disconnected JB4 from OBD port and turbos and car seemed to start and rev until i put it in drive. Then was drive-able limp mode - about 2500 RPM and shift gears. Car threw CEL but I could not get JB4 to read it before I disconnected it. Any ideas? Will the car go back to normal mode if I let it sit or do I have to clear the code?
 

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Newport, Oregon
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Uh oh - Limp mode. Added some Octane boost (just used the STP Stuff), and then topped off with more 93 octane about 2 gallons (tank was full). Drove for about 40 minutes and car seemed to run better and knock seemed to go away.. Then stopped for about 10 mins to pick up lunch...came out started car and all was good...pulled out to busy street and went into limp mode - no throttle at all...just idle. JB4 was disconnected and would not connect. Messed with the JB4 under the hood a bit and it connected but still full limp mode - no throttle whatsoever. Then I disconnected JB4 from OBD port and turbos and car seemed to start and rev until i put it in drive. Then was drive-able limp mode - about 2500 RPM and shift gears. Car threw CEL but I could not get JB4 to read it before I disconnected it. Any ideas? Will the car go back to normal mode if I let it sit or do I have to clear the code?
I would expect the car to go back to normal if the DTC was temporary and you cycled the ignition.

You should call BMS and ask them what's going on. If your settings are proper and there's no wiring/harness problem then they may suggest reflashing the firmware to the current version if you haven't done so already. I don't think octane is your problem. How long have you had the JB4 and what firmware version are you running?
 

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Murrieta, CA, USA
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I hope it's not because you bought the ebay harness and not the BMS harness.
 

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St. Louis, MO
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Discussion Starter · #24 ·
I'm on version 8 the latest stable version. I've had the JB4 for several months now. Only previous issue was having to reinstall the app due to it ceasing connection via blue-tooth. That was 2-3 months ago.
 

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Newport, Oregon
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Call BMS would still be my suggestion. You might also disconnect the fuel wires and EWG wires and see if the JB4 operates properly on its own. Add back the others one at a time and see what happens. Have you checked your harness connectors for bad pins? Checked continuity for each wire in your harnesses?
 

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St. Louis, MO
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Discussion Starter · #26 ·
Limped her home last night and then removed the negative battery terminal. I opened up the JB4 and checked all of the pins, positions, and condition of the board. Everything checked out fine so I put it all back together carefully. Re-plugged in the JB4 turbo connectors (I left the EWG connectors in place as they are a bit of a pain to unplug). Put the terminal back on and everything was back to normal. Car was running great this morning.
 

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Newport, Oregon
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So your fuel wires and EWG wires are also connected when you say everything is back to normal?
 

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St. Louis, MO
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Discussion Starter · #28 ·
Yes, I never removed the EWG or Fuel Wires so all were attached after I reconnected the battery terminal. Car started and drove normally. This morning I drove it hard and it performed excellent. I have EWG set to the recommended starting values, Fuel Wires enabled, and running Map 5.
 

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Newport, Oregon
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Yes, I never removed the EWG or Fuel Wires so all were attached after I reconnected the battery terminal. Car started and drove normally. This morning I drove it hard and it performed excellent. I have EWG set to the recommended starting values, Fuel Wires enabled, and running Map 5.
Evidently, a temporary DTC that put you in fail-safe mode. Drive on! My fuel wires and connector kit will be here Saturday.
 

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St. Louis, MO
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Discussion Starter · #30 ·
Yep - Car sat for several hours but would not snap out of limp mode. I didn't have any tools to get the battery cable loose so I limped it home. I had removed the original JB4 turbo connectors and installed the engines plugs directly but that didn't help. JB4 was also unplugged from OBD port. Does anyone know any other way to reset the ECU should this blip occur again? Once I got it home I tried erasing all of the DTC codes but it did not help.Codes were 2122, 2138, 643, 222, 123, 146, and 004B, along with a C1130 ABS code! YIKES! I promise no codes before the "event'!

Weird thing was that the Entertainment system remembered by radio presets but "forgot" the correct time.
 

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Newport, Oregon
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Most of those DTCs are throttle/pedal position faults with a O2 sensor fault and wastegate valve stuck fault for good measure. The C1130 DTC means a malfunction was detected in the ECM system. Could be ABS-related but could also be something else like a harness/connector, CAN comm line, battery or fuse/fusible link problem.

When reporting DTCs, please include the letter preceding the number and include leading zeros. Makes looking up DTCs a lot easier.
 

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Murrieta, CA, USA
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I didn't know there were any other codes than P codes. I guess there is B, C, and U as well?

 

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Discussion Starter · #33 ·
Sorry Avendis - didn't mean for anyone to diagnose them...I was just making a point that there was a boat-load! Scanner gave the descriptions too and they all seemed JB4 function related so I didn't give them much thought. My "diagnosis" was the JB4 blipped (lost power or connection momentarily) and the car went haywire. Its just sitting in the brake booster compartment so maybe it jolts around a bit too much. Maybe I'll zip tie it down to secure it.
 

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Newport, Oregon
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Sorry Avendis - didn't mean for anyone to diagnose them...I was just making a point that there was a boat-load! Scanner gave the descriptions too and they all seemed JB4 function related so I didn't give them much thought. My "diagnosis" was the JB4 blipped (lost power or connection momentarily) and the car went haywire. Its just sitting in the brake booster compartment so maybe it jolts around a bit too much. Maybe I'll zip tie it down to secure it.
I always look at the DTCs people post. It helps narrow down where to look and what to check. Yes, I would say they are all related to the JB4. Let's face it, cars are simply rolling computer networks and occasionally they need to be reset to clear their pea brains. Securing your JB4 isn't a bad idea. Mine's inside a zip-lok freezer bag and jammed in by the master cylinder so it doesn't move.
 

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2016 Q50 Premium w/Tech Pkg. JB4, Helmholtz
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Jcb, I'm glad you were able to get your car running again. I'm about to pull the trigger on the Ebay wires, and have a couple of questions for you. Was the 3 feet enough for the driver side? Did you run into any issues accessing the plugs? How easy was it to snap the connectors on and off?
 

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Newport, Oregon
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Jcb, I'm glad you were able to get your car running again. I'm about to pull the trigger on the Ebay wires, and have a couple of questions for you. Was the 3 feet enough for the driver side? Did you run into any issues accessing the plugs? How easy was it to snap the connectors on and off?
Read this thread. EWG wire discussion starts on page 3 or so.

 

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St. Louis, MO
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Discussion Starter · #38 ·
Chernomorez - yes, the wires were very good quality and plenty of length. The pins were stout enough that I wasn't overly worried about breaking them when "jamming" them through the JB4 adapter. They even came with 2 little tools that I had no idea how to use (probably SHOULD have been used to help get the pins in place within the JB4). Anyway, I did it with my fingers and small pliers. The plugs in their harness fit perfectly - quality was great on them. The car's wastegate plugs were a challenge to get off on both sides - just things in the way and not enough hand space - once I got them off, it was much easier to plug the new harness in its place.
 

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Discussion Starter · #39 ·
Ddn Spider - are you looking for a JB4 log from me documenting the event? I was not logging when the event occurred that put me into limp mode, and JB4 was not functioning properly during limp mode (fairly certain it causes it by either losing power momentarily or a loose connection to the turbos.
 

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2016 Q50 Premium w/Tech Pkg. JB4, Helmholtz
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Just got the EWG wires from EBay. Slightly different color coding, but instructions were included as to which pin goes to which position. Also the seller included a tool for removing pins from harness. Will try the install later on this evening.
 
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