Recently, my check engine light came on, an has been on for 2 weeks. Sometimes the car misses when its cold, but I can't notice any other difference. Any one else had this problem or know how to fix it? My guess is the fuel pump, or the AEM Short Ram.[?]
Don't guess at the problem. Diagnose it correctly. You will need a OBD II code reader that plugs into the diagnostic output under the dash. Some Autozones and larger car parts dealers have readers and will provide this service often for free. The reader will provide a numerical code. You look the code up in the manual that comes with the code reader or a repair/shop manual. The code will identify the problem. Don't start replacing parts....its false economics. OBD II readers can be purchased fro less than 100.00 or can be rented at part stores as well.
Hold down your odometer reset button, turn your key and start the car, continue holding the button for a few seconds, and you'll get into "test mode", where you can scroll through a bunch of different readings by pressing the button.
As most of you know, you can enter a test mode on the instrument cluster but only a few of the functions have been figured out, untill now. Here is a list of all the functions:
1 Gauge Sweep All gauges carry-out sweep
2 LCD Test Makes all the LCDs light up
3 Bulb Test Lights all functioning cluster bulbs
4 Rom Level Displays the instrument cluster ROM revision level
5 NVM Level Displays the instrument clister NVM revision level
6 DTC Diagnostic trouble codes
7 Road speed MPH
8 Road Speed Kmph
10 Fuel Volume
11 Engine cooland temperature
12 battery voltage
13 ABS Fail Displays ABS RAW input (H=over-charging or battery L=Ground)
14 Electronic brake distrubution failure ^
15 Illumination H=on L=off
16 Crank sense H=ignition L=ground or over-charging
Also i am working on thoes DTC Codes ill get back with you on that as soon as i find out
Q: DTC codes are those the check engine codes the ecu throws up?
A: Yes. DTC = Diagnostic trouble code
**All this info was brought to you by FF member dustinkimble
I actually had a similar problem with my first focus. It was the power steering pump that set it off, or so i was told, i knew the pump had t be replaced when i noticed it was extremy hard to turn the wheel when driving. .. and so be it, the light came on...
Like Focal said... don't go by the DTC's on the cluster. I have a few codes in my cluster now and there is no CEL on. So see if there is anything you have done prior to the light coming on, if not take it down to the dealership if you're under warranty if not get is scanned for free ant autozone. Sounds like a DPFE to me... but that's my guess. Foci are known for that issue.