I have a 2005 R53 JCW with 29K miles that I use for track and autocross. After having a performance ECU tune by O2 Motorsports and installing a SprintBooster, I have had a lot more warning lights flashing, mostly at track events, but sometimes just under normal driving conditions.

For instance, at a track event last Saturday, my ABS light went on during the first session and indeed the ABS stopped working. Went in, let the car cool down, then restarted the car and headed toward the track mechanic and the ABS light cleared after a 100 yards. Brakes worked fine the rest of the day.

Later, the same day, the Service Engine Soon light went on. After the session I checked and it was a P0108 Manifold Absolute Pressure. I've seen this before and ignored it. The light later cleared.

On the way home after the event, about 30 miles out, the EML light went on and the car went into limp mode when pulling away from a stop sign. Pulled off the road, shut the car down, restarted and the light cleared and drove the remaining 140 miles home with just the Service Engine Soon light lit (P0108 and P1685 SKIM Invalid Key).

Next day the car started and the light had cleared.

So is this kind of thing to be expected once the car has been so modified?

Deven

 

Absolutely not!

I've never had issues with ABS other than occasional "ice mode". May have a wheel sensor going bad, or they could need to be cleaned.

I'd change the MAP sensor - its relatively cheap and good maintenance.

As for the rest, I'd back the tune out and see if things cleared up.

 

I'll check into your suggestions -- Thanks!

My car is also British Racing Green -- only way to go.

Deven

 

check your crank pulley. With the map fault and Limp mode that is common for a failing crank pulley to cause. Also at the track the stock one gets hot and that is when it fails or slips. Go with an ATI damper and you won't have that issue anymore.

 

I have the ATI Super Damper (bought it from you along with much more ). Should I have the belt checked?

 

Took the car to my local mechanic so he could perform some diagnostics. Here's his feedback -- let me know what you think:

Car passed all diagnostics. Sprint Booster was off.

ABS lights: During my first track session of the day, I most likely had DSC on (this is my habit, for later sessions I turn it off). Excessive front wheel spin probably triggered the ABS light. Solution: always turn off DSC on the track.

P0108 Boost Manifold Pressure: This was recorded 18 times, always at 6700 rpm. Solution: see if custom ECU tune can be tweaked to avoid this.

P1685 Throttle Body: This was recorded once. All the sensors checked out fine. There are a couple of threads in the forum that describe pretty similar situations to mine (search on P1685, also see https://www.northamericanmotoring.co...ighlight=p1685). This issue does concern me because it could make it difficult to return from the track. Solution: Not clear. Maybe Sprint Booster related? Hopefully get some feedback here.

Deven

 

Can you back the tune out? I'd bet both the codes are tune related. With torque based ECUs you need to do track testing if you used an inertia dyno for tuning. The dyno can't load the engine as much as the car does on a track. Therefore you can mess up torque table entries (or entries in other tables which the ECU uses to compute requested torque) using an inertia dyno which you discover at the track.

I'm no tuning expert, just been reading up to try and understand what my tuner is doing so I can give good feedback.

 

I am hoping to hear back from O2 Motorworks!

 

Had a chance to talk to O2 Motorsports about whether their ECU tune may be the cause of the warning lights. Steve was very helpful but suggested looking elsewhere for the cause. Likely suspects are the ABS and throttle body controllers. Since these controllers still pass the diagnostics, I plan to keep an eye on them.

We did agree that it was worth upgrading to a Detroit Tuned Bypass Valve.

I have another track day coming up next weekend. I'll report back how things work out.

 

This is slightly off topic but can an iphone app with obd scanner get the same codes? or is it something that requires a special machine to read it?

 

Yes. I use the GoPoint BT1 OBD II scanner with my iPhone. It reads the codes' numeric values just fine. Sometimes the descriptions are not quite the same as the ones generated by my mechanic's scanner.

It doesn't seem to be able to reset the codes however.

The GoPoint apps are a little clunky, but the device works fine with other apps.

 

Finally got back to the track yesterday after a very long absence and here is an update:

Took the car in to address the issues described in the first post here and -- as usual -- took the opportunity to do some more upgrades (in this case a Mishimoto Aluminum Performance Radiator, Aluminum "Exact-Fit" Coolant Tank, all new coolant hoses, and H2O temp, oil pressure, and A/F ratio gauges).

Two things were done to address the P0108 Boost Manifold Pressure error: installed a Detroit Tuned Bypass Valve and replaced a damaged activated charcoal filter.

While things were apart, I asked for the supercharger oil to be changed. There was only 2oz of oil in the SC and it was badly discolored. Decided to replace the SC with a rebuilt one from WMW.

Nothing specifically was done to address the P1685 Throttle Body error since the Throttle Body itself tested OK. The hope was that all of the above changes may in some way solve it.

Also nothing done about the ABS light other than turning off DSC on the track.

The good news is that the Boost Manifold Pressure problem seems to have been solved -- didn't get any P0108 errors!

On the ABS front, I was on a new (to me) track and taking it easy. I did leave DSC on the first session and had no problems. DSC remained off the rest of the day. However, on this track I was not driving nearly as aggressively as I normally do (a rare sign of good sense given all the walls).

Unfortunately the P1685 error showed up again at the end of my 200 mile drive to the track four times and once on my return trip the next day. The pattern is always the same: a long steady highway drive followed by coming to a stop, then the EML light glows and the car goes into limp mode. Please note that this does not happen every time you come to a stop (that would be annoying!).

So before participating in the track event I spoke with my mechanic and he thought this pattern probably meant that the throttle body was failing after sustained heat build up (i.e. long highway driving) and that the track event would not induce the problem (track sessions are only 25 minutes and spaced 90+ minutes apart). Turns out he was right as the car performed flawlessly at the track (wish the driver had ).

Looks like the next step will be to replace the throttle body. I'll post an update here on the results.

 

After reviewing the situation further with my mechanic, we decided to change out the map and tmap sensors first. Only if that failed would we replace the throttle body.

After another track day (340 travel miles plus 90 track miles), the car is running fine -- no engine lights, no limp mode, just runs like normal.

So looks light we've got everything sorted out. If not, you'll see it posted here.

 

I just had the same thing with ABS light coming on about 10 minutes into a track session. DSC was off the whole time. There was some wheel spin but nothing like when autocrossing (and it's never happened then).

Brakes still felt fine, but I took it easy the rest of the session. After the car cooled and restarted the light went off.

I was thinking maybe a sensor overheating and wasn't reading properly... really have no idea.