2003 F150 - Flashing ALT Light

[utkatana]

My first post!
I'm stumped.

I purchased my '03 F150 Bi-fuel a little over a month ago, and the thing runs great...on gasoline. From day one, the ALT light has blinked continuosly when the key is turned on. The truck was a Questar vehicle and they said that it would intermittently run on CNG.

I got a CNG service manual for the '03 trucks and it indicates that a steady flashing ALT light means that an "emissions critical diagnostic trouble code" has been recorded. I hooked up an OBDII code reader to it tonight, and it showed no trouble codes. I'm guessing it just reads the PCM and not the AFCM.

Anybody have this problem before? Do I need a different OBDII code reader to read the AFCM codes? (I'm using an Innova 3100) I'm not sure where to go from here. Any suggestions? Thanks!

[Lancer Automotive Group]

Re: 2003 F150 - Flashing ALT Light

You need the Ford IDS system to read the AFECU codes, All Ford Delerships and most good CNG shops will have the IDS system.

[wmarsden]

Re: 2003 F150 - Flashing ALT Light

Yes. To read the codes stored in the CNG portion of the system you have to have a special reader. To my knowledge, Champion Ford in Salt Lake is the only one I know of in Utah that has this - and they charge for just reading your vehicle.

Anyone know of anybody else that has the reader in Utah?

[utkatana]

Re: 2003 F150 - Flashing ALT Light

This is more of a 'bump' than anything else. I'm still having the same problem with my truck. I've gone through and cleaned out the filter (it was disgusting) and checked to make sure I have pressure to the fuel rail. All of the connectors seem fine (FRT, FRP, FTP). I'm still getting a flashing ALT light, and have no idea why. I'm hoping someone has had a similar experience with a successful resolution.

Does anyone know how to read the AFECU codes without having to go to the stealership, are there aftermarket readers, or is the Ford IDS system the only one that works? If the IDS is it, is there someone that will do it free?

Alternatively, I suppose I could go through and test each of the components, but I don't know their specs. Any help would be appreciated. This forum is awesome!

[larrycng]

Re: 2003 F150 - Flashing ALT Light

The old NGS (before the IDS) will read the if you have the "Green" card. Hickock, the company that made them was still updating the as of about 3 years ago. The one I had would read CAN system and AFECU (with proper update card). Check with www.aeswave.com Automotive Electronic Services in Fresno, Ca. Ask for Carlos, he can tell you real fast if it is available. The Ford dealer may have one laying around collecting dust and not know what it is for (Green labeled card)

Larrycng

[utkatana]

Re: 2003 F150 - Flashing ALT Light

Thank you very much, sir! I'll see what I can find!

[utkatana]

Re: 2003 F150 - Flashing ALT Light

Just a follow-up: I took my truck in to Lancer Automotive, and they diagnosed my truck. (BTW, they were awesome, and did a great job - thanks, guys!) I guess my high pressure sensor is reading zero (but fuel rail pressure is normal, so something's up with the sensor/wiring).
Has anybody had any experience with this, had the same problem, found a solution? Its $300+ for the part from Ford. Just exploring my options before spending that much money.

[Astout]

Re: 2003 F150 - Flashing ALT Light

my dad had a 2000 bi fuel f150 and he had a blinking light on his so i changed the spark plugs and some of the 02 sensors. made the light go away.

[locosmotion]

Re: 2003 F150 - Flashing ALT Light

Check the compuvalve o2 sensor intercept harness to make sure the o2 sensor signal(s) pass through the compuvalve then to the original harness. I've seen this twice on contours both with flashing Alt Lights.