I have a 98 Expy. I only have one key, I am adding an autostarter so I ordered a few ford spares off eBay. Had them cut at the hardware store and brought them home. The place I bought the keys from said the 98 Expy can have additional keys programed with just one orginal key. So I followed the steps they gave me. I inserted the original key turn to on and then turned off, then put the new key in within 15 seconds and turned it to on. When done the new key started up the truck no problem, tired it a couple of times also with no problem. So at this point I am very excited. Well I went to go to the store this afternoon and happen by chance grabbed the old original key. Got in the truck and went to start it but the theft light flashed and died. So I tried the newly programmed key at it started up fine. When going to come home from the store went to start the truck and niether chipped key would start the truck. Both would flash theft and not start. So I happen by chance had a normal non chipped key on my keyring for just opening the door. Tried it and the truck started right up and I drove home. I have shut off and started a couple of times since then thinking it was a fluke, but the only key that will work is the non chipped one. Anybody have any idea's ? I am lost, do I have to take it to the dealer and have the computer reset or what? Sorry about the long post I wanted to give the whole story. Thanks for any help.

 

If you used the non chipped key, as long as a programmed chip key is within range of the PATS antenna I believe it should start.

But sometimes having too much metal (i.e, keys) on the key ring can block the transponder from picking up the PATS signal and reflecting it back.

 

I am lost. I don't know where to start. The whole reason I bought the keys off eBay was to try and get around from goin to the dealer. No it looks like I made matters worse. I dont know if unplugging the battery will help or not.

 

Just a little UPDATE
I tired with just the non chipped key with the other keys in the house. Truck still started up fine.

 

Wow! I am now confused. Could it be your non chipped key is actually a chipped key?

The 1997 and 1998 Expy used a PATS Type A and it provides two methods for programming keys without using the dealers NGS scan tool and requires that you have only one programmed key available.

One method is referred to as "Key Programming - New Key". It will clear all chipped key codes from memory and just insert the "new" key's code in memeory.

Second method is referred to as "Key Programming - Spare Key". It does not clear the PATS memory and just adds the new chipped key to PATS memory (if there is any room in memory for an additional code. The Type A PATS memory has room for 16 chipped keys.)

When you say "neither chipped key would not start the truck", do you mean the truck cranked over and didn't start, or do you mean that there was a "no-crank" condiction?

IIRC, a no-crank condiction on a Type A PATS is not a PATS issue.
If you know someone that has a good scan tool, there may be some B (for Body) codes stored in the PCM to help diagnose.

Also, check with you key supplyer to be sure the keys are "Ford Qualified".

I'm outta ideas . . . .

 

I keys I bought look like factory ford keys. The non chipped keys will start the truck but then it will die. Update, tonight my wife got home and said that the original chipped key is what is working night now. So I went out there but both of the chipped keys start the truck tonight. I am wondering if I used the new key programming so I can clear the memory and then add the keys one at a time. Or should I just take it to the ford dealer and then this straighten out there. They should be able to add the extra keys for me I would think. Even though I would rather do it myself and save some money. What do you guys think.

 

That's what it should do.

Good! So you didn't erase the other key codes.

Good! No PATS issues.

 

I still am lost as to what is going on. I will have to see what happens when I try the other newer keys I ordered and try to program. There is a non factory keyless installed right now. I wonder if who ever put it in messed up the wiring and is causing this problem.

 

What is installed on the truck now, you mentioned a nonfactory keyless. Is there a key hidden in the truck to allow it to start or is it using a bypass module?

 

No key in the vehicle. It is just a keyless entry.

 

Have you checked codes? If the key is programmed incorrectly it will at least give you a code. I don't know if it sets the SES light, but it does leave a code.

 

I have not checked codes yet. I am thinking about buying an Auto Enginuity, or taking it to the dealer.

 

FWIW, I programmed my own keys for my 04 Expy using AE. I also changed the tire size for my speedo correction on my Super Duty. Between those two things and the assistance it has been in diagnosis it is worth its weight in gold. I got mine from Clay at RiffRaff.

 

Well that is good to know. The thread I am watching it is still up in the air about programming keys. I will have to look into it more. Called the dealership a d the said they would only charge me $45 to erase the memory of the keys and to program all the new keys with new codes. But still looking at an AE.

 

The '97-'98 Expys have the type A antitheft system and you shouldn't need a scan tool to clear all key codes from PATS memory and just insert your new key. (See post #2 above.)

To remove all key codes and program a new key you will need a transponder key with the correct mechanical cut to fit in your ignition. Then follow the procedure below:

1. Insert the nonprogrammed key in the ignition and turn to RUN.

2. The theft light should start to flash rapidly.

3. After 15 minutes of flashing the theft light will stop flashing.

4. Within five minutes after the flashing stops, turn the ignition key to OFF and then back to RUN.

5. After flashing again for 15 minutes the flashing will stop.

6. Within five minutes after the flashing stops, turn the ignition key to OFF and then back to RUN.

7. After 15 minutes of flashing the theft light will stop flashing.

8. All originally programmed keys are now erased from PATS memory and only the key in the ignition is programmed.

9. Additional keys may now be programmed using the "Spare Key" method which can add keys without resetting PATS memory.

Again, what with the modifications to your truck's wiring who knows what might be causing your issues. . . . ..