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2016 Q50 Red Sport AWD
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12 Posts
Discussion Starter #1 (Edited)
Hi everyone

Was driving yesterday in the rain and got on it.. had some wheel spin then the car went into limp home mode.
Restarted car and as soon as i made more than 3-4 psi the car went back into limp home mode.
I checked the JB4 to see if the pins were loose looks like all is good. It has been running fine for months and have not touched anything.
OBD code shows 2586 and the VDC light came on.
engine sounds fine.. starts fine.

Any clues?
thanks!

Update: I tried dropping to map0 before i remove the jb4 and it seems to be fine made it to 13psi no issues. As soon as i go to map2 i get the VDC and limp mode when i give it some gas where the torque really kicks in.
 

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Super Moderator
Newport, Oregon
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9,342 Posts
Hi everyone

Was driving yesterday in the rain and got on it.. had some wheel spin then the car went into limp home mode.
Restarted car and as soon as i made more than 3-4 psi the car went back into limp home mode.
I checked the JB4 to see if the pins were loose looks like all is good. It has been running fine for months and have not touched anything.
OBD code shows 2586 and the VDC light came on.
engine sounds fine.. starts fine.

Any clues?
thanks!

Update: I tried dropping to map0 before i remove the jb4 and it seems to be fine made it to 13psi no issues. As soon as i go to map2 i get the VDC and limp mode when i give it some gas where the torque really kicks in.
I'm assuming the DTC is P2586? If that's the case, that DTC is telling you that the electric wastegate control valve position sensor on the driver's side is bad or the circuit is open or shorted. I'd suspect a JB4 wiring harness/connector problem on the driver's side.
 

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2016 Q50 Red Sport AWD
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12 Posts
Discussion Starter #3
I'm assuming the DTC is P2586? If that's the case, that DTC is telling you that the electric wastegate control valve position sensor on the driver's side is bad or the circuit is open or shorted. I'd suspect a JB4 wiring harness/connector problem on the driver's side.
Thanks for the info.. ill take a look at the wiring again. ill try running without the wastegate wires also and report back.
 

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Super Moderator
Newport, Oregon
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9,342 Posts
I'd disconnect the fuel wires and EWG wires and run only with the JB4 on a couple maps to see if the DTC appears. If not, add the fuel wires and test again. Then the EWG wires. I suspect you'll get the DTC with only the JB4 connected and running on any map that adds more boost (not map 0).

The thing that I can't figure out is your VDC warning light.
 

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2016 Q50 Red Sport AWD
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12 Posts
Discussion Starter #5
I'd disconnect the fuel wires and EWG wires and run only with the JB4 on a couple maps to see if the DTC appears. If not, add the fuel wires and test again. Then the EWG wires. I suspect you'll get the DTC with only the JB4 connected and running on any map that adds more boost (not map 0).

The thing that I can't figure out is your VDC warning light.
Pulled off the Wastegate wires and can run maps no problem now.
Checked the pins again and all looked seated fine. Ill run a continuity on them on the weekend and see if any connections are bad.

Driving for all this time with the JB4 wastegate wires hooked up and and now driving without them I can really feel the difference in the low end torque. That kick in the ass is not as powerful from a rolling start as it was before.
 

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Newport, Oregon
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Pulled off the Wastegate wires and can run maps no problem now.
Checked the pins again and all looked seated fine. Ill run a continuity on them on the weekend and see if any connections are bad.

Driving for all this time with the JB4 wastegate wires hooked up and and now driving without them I can really feel the difference in the low end torque. That kick in the ass is not as powerful from a rolling start as it was before.
I'm assuming you've checked to make sure the EWG harness wires are connected to the correct pins in the JB4 connector, that you've entered the EWG values in the proper fields on the JB4 User Adjustment page and you've set options/FUD bit 6 to On?

If that's all good, then checking continuities is in order. Your focus should be on the driver's side harness connectors since that's where the DTC is pointing. Do look at your JB4 harness connectors that connect to the driver's side TMAP sensors also just to be sure.
 

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2016 Q50 Red Sport AWD
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12 Posts
Discussion Starter #7
I'm assuming you've checked to make sure the EWG harness wires are connected to the correct pins in the JB4 connector, that you've entered the EWG values in the proper fields on the JB4 User Adjustment page and you've set options/FUD bit 6 to On?

If that's all good, then checking continuities is in order. Your focus should be on the driver's side harness connectors since that's where the DTC is pointing. Do look at your JB4 harness connectors that connect to the driver's side TMAP sensors also just to be sure.
The strange part is the wires worked for about 2 months no issue. Bit 6 is on, let me see if I inadvertently touched the user adjustment page settings while scrolling.
 
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