Thursday, February 13, 2014

CEL on our Exige 'S' (DTC P0101 Troubleshooting)

After a spirited mountain run, our test Exige, 'Switchblade', threw a CEL (Check Engine Light). The scanner told us we were getting 'P0101' which translates to "Mass or Volume Air Flow Circuit Range/Performance". This means that there is an issue regarding the readings between the MAF (Mass Air Flow) sensor and the MAP (Manifold Absolute Pressure) sensor. The probable culprits? A dirty MAF, MAP, or leak somewhere in the intake system.

Let's try some simple tests/ fixes. First; we cleaned out the MAF by removing it from the air filter box and giving it a good cleaning using a MAF/MAP cleaner. This spray is available at the local auto parts store. We also cleaned off the MAP using the same stuff.  


You can run the risk of damaging the sensitive wires in the sensor and then you'll be left with having to buy new parts.

That first test didn't stop our code from coming back, so the next thing we did was search for vaccum leaks.  We grabbed a few cans of brake cleaner and sprayed the intake components of the engine while another tech kept an eye on the tachometer. We knew we found the leak when the RPM's started to climb after soaking the elbow that attaches to the supercharger.

We let the car cool off before diving in and taking things apart. There is a O-ring seal between the supercharger and the outlet elbow that has been an issue on a certain number of these factory-supercharged cars. Sometimes the rubber seal rips, sometimes it shrinks... either way, it's causing a boost leak. No Bueno.

If you've found an intake leak at this connection, you can follow these steps. Begin by disconnecting the MAP harness from the MAP sensor on the intercooler. Un-secure and remove the intercooler pipes. A good way to remove these pipes is to slide the rubber cup-link back to give you more space to pull them out - especially if you may have one of our BLADE kits installed.

Next, disconnect all of the ducting from the intercooler. Unbolt the intercooler, carefully remove it, and set it aside for inspection and cleaning. For those of you using any of our BLADE kits, remove the lower heat shield as this will be in your way.  With everything removed, you can now see the outlet elbow that sits on top of the supercharger held on with four 10mm bolts.


Unbolt the elbow and pop the elbow off. There should be little resistance so it should come off by hand. A light tap with a rubber mallet will break it loose if it is giving you a little fuss coming off.


The seal may be stuck to the elbow when removing it from the supercharger (as is shown in the photo below), so stay vigilant as not to allow it to fall into the blower. You will want to clean off the surface of the blower by spraying some brake cleaner onto a red rag or blue shop towel.

Use some blue painters tape to cover the hole when you are done cleaning the surface of the supercharger to keep foreign objects from falling in.  Clean off the surface of the elbow and inspect for any signs of major damage. There may be a little pitting on the surface -this is OK as they come this way from the casting process.

Replace the old o-ring with the new one and bolt the elbow back onto the supercharger. Make sure to torque the elbow down to 18 ft-lbs. using some blue Loctite. Don't forget to re-install the actuator bracket back on before torquing the 10mm elbow bolts to spec as well. When you are finished inspecting your intercooler for any debris and/or oil, begin the reverse process of re-installing all the parts.

Be sure to clear the ECU codes and test drive it for a few miles to make sure that the issue has been resolved. 

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