CCC Newsletter for this month.

How many times have you been driving along and that pesky ol' ‘Check Engine’ light comes on! Well, if you’re driving a C5 there’s a way you can see what the problem is, and you can also clear the light (turn it off). This procedure can be accomplished while you are driving, or while parked with the key in the ON position, engine running or not. By pushing a certain combination of the buttons on the Driver Information Center (DIC), you can “pull the code”, and then if desired clear the malfunction. Here’s the procedure: First, if you have a warning message displayed on the DIC, push the ‘Reset’ button to clear it. Then push and hold the ‘Options’ button while you push the ‘Fuel’ button 4 times. The first codes displayed will be the current codes applicable to the Power train Control Module (PCM), and should be the code that turned on the Check Engine light. Each code will be displayed for 3 seconds. If there are any old codes still in memory but not affecting the operations of the vehicle, it will end with an ‘H”. A current code will be something like “P00175”, which is fuel trim system rich bank 2. An old history code would be like”P1415H”, which is a previous problem with the AIR system bank 1, (bank 1 is the left side of the engine, bank 2 right side). By now you’re thinking, this information is no good to me if I don’t have a list showing what each code means. Ok, to fix this, I have sent Brent the list of codes affecting the PCM and will ask him to attach a link to “Code List”. ( Click here for code list. )

When you are ready to clear the code do this: After all the codes have been displayed or at any time during the display process press ‘Reset’ to enter Manual Configuration mode, the DIC will then display “# Codes” for each module. (An example of a module is the PCM, another is the Traction Control System [TCM]). Once in the Manual Configuration mode press ‘Reset’ again until the display reads “No Codes”. To exit the diagnostic mode press ‘E/M’ button. Or, you can go to your nearest Auto Zone and they will hook up a diagnostic tool to the OBD II port and pull the code, then hope to sell you a replacement part to fix the problem.

I’m told this diagnostics procedure I’ve described herein does not work on C6’s. This is another reason I’m hanging on to my C5’s. Other reasons include: C5’s have a real fuel filter that can be changed, they are easier to tune, they don’t have fancy electric buttons to open the doors, and the trunk is bigger!! All that said, I still wouldn’t mind a new ‘o8.

Bruce