JB4 Harness Issue? (CEL/Codes)

[inevitab1e]

I'm trying to figure out what's randomly making my car throw CEL and codes.
Problem mostly happens with Map5. Is there a way to test the harness to make sure it's not damaged and working properly? I've had this issue since I purchased the JB4 a month ago.

Codes:
2C58
2C6F
281A
281B (I sometimes get this code in addition to the 3 above)


The problem appears to come and go when it wants to. I can start the car, not get a CEL and drive fine. Other times I start up the car, get the CEL and reduced power.

[Stewy_604]

2C58 is charge-air pressure control (monitors the DME's de-activation of active boost)
2C6F is boost pressure sensor (monitors the wire to the boost pressure sensor)
281A is absolute pressure sensor (monitors the intake-manifold pressure sensor's upper voltage limit)
281B is absolute pressure sensor (monitors the intake-manifold pressure sensor's lower voltage limit)

Have you checked all your connectors on the install? I would try the easy things first, re-seat all connectors and check for possible damage (rub through, melting, critter-chew, etc...). Definitely sounds boost related. Are you a harness A or B JB4? Was the JB4 purchased brand new or used?

[inevitab1e]

Originally Posted by Stewy_604

2C58 is charge-air pressure control (monitors the DME's de-activation of active boost)
2C6F is boost pressure sensor (monitors the wire to the boost pressure sensor)
281A is absolute pressure sensor (monitors the intake-manifold pressure sensor's upper voltage limit)
281B is absolute pressure sensor (monitors the intake-manifold pressure sensor's lower voltage limit)

Have you checked all your connectors on the install? I would try the easy things first, re-seat all connectors and check for possible damage (rub through, melting, critter-chew, etc...). Definitely sounds boost related. Are you a harness A or B JB4? Was the JB4 purchased brand new or used?

Thanks for the reply. Harness B JB4 purchased new a month ago. I've played with the connectors and can't pinpoint issue. That's why I was curious if there was a way to test the harness. Pins/Plugs/Adapters. I'm thinking there's something loose somewhere but haven't inspected anything (anally). Been like this from day 1.

If a pin in a plug isn't seated properly, would that cause this issue? I also have a strange electrical sound which is turned off/on by menu 4/5 (flap) toggle

[Stewy_604]

Next steps might be contacting BMS directly, they've got pretty good support from what I hear.

If you hook up the stock connectors, do you still receive the codes? I'm thinking its something with that boost solenoid connector, perhaps a pin not seated properly.

[inevitab1e]

Originally Posted by Stewy_604

Next steps might be contacting BMS directly, they've got pretty good support from what I hear.

If you hook up the stock connectors, do you still receive the codes? I'm thinking its something with that boost solenoid connector, perhaps a pin not seated properly.

I've made the same thread at N54 in the support section. No help yet.

[houtan]

Originally Posted by inevitab1e

I've made the same thread at N54 in the support section. No help yet.

Email Terry directly.

[Xer0449]

Chiming in here:

I had the same exact codes. Turned out to be the wiring for the JB4 connect kit.
Assuming you also have the connect kit, there's a wire going to it that expects 5v and is getting 12v (or vice versa!)

Here's what fixed it for me: http://www.n54tech.com/forums/showthread.php?t=43267

Switched the wires, all codes went away instantly.

[inevitab1e]

Originally Posted by Xer0449

Chiming in here:

I had the same exact codes. Turned out to be the wiring for the JB4 connect kit.
Assuming you also have the connect kit, there's a wire going to it that expects 5v and is getting 12v (or vice versa!)

Here's what fixed it for me: http://www.n54tech.com/forums/showthread.php?t=43267

Switched the wires, all codes went away instantly.

Thanks for that, I made a post at that thread. I had my connect kit spliced into the JB4 red wire with the fuse. Can't believe I've been driving with it like this throwing CEL's and codes for a while.

Maybe this will explain the strange electrical noise I randomly get that seems related to the CANflap and/or wastegate position.

[Xer0449]

Let me know how it goes. Ever since I had the JB4 put in, the cars been 'different' regardless. I'm excited for MHD to become available for my DME...