91 4.0 codes

[mobile madness]

i know my truck has obd1 but ive never seen a plug under the dash for it. and i have no idea how to check codes. my rear antilock is what making me crazzy. i though it was the spd sensor on top on the pumplin so i replaced it and nothing. id also replaced my front brakes with calipers and shoes and for the drums id gotn new shoes and wheel cylinder and all the harware.

 

[spraymonkey]

looks under your hood on the driver side kinda looks like this pic.

 

[spraymonkey]

Put the jumper wire as indicated between "Self Test Input" and "Signal Return� Ground"

Get ready to count, and turn the Ignition Key ON, BUT DONT START IT!.

It may take the computer 30 seconds or more to go through its self diagnostics, it will then begin to flash your codes. All you have to do is count.
There is a 2 sec delay between digits, and 4 sec delay between codes (if there is more than one code)

Also if there is more than one code the computer will flash the same codes a second time. When it is done sending the "On Demand" codes there will be a six to nine second delay, Then it will send the "Continuous Memory" Codes... (the ones it stored in memory during the last 40 trips to the store.)

Using the same method... 2 sec delay between digits, and 4 sec delay between codes.

 

[mobile madness]

Put the jumper wire as indicated between "Self Test Input" and "Signal Return� Ground"

Get ready to count, and turn the Ignition Key ON, BUT DONT START IT!.

It may take the computer 30 seconds or more to go through its self diagnostics, it will then begin to flash your codes. All you have to do is count.
There is a 2 sec delay between digits, and 4 sec delay between codes (if there is more than one code)

Also if there is more than one code the computer will flash the same codes a second time. When it is done sending the "On Demand" codes there will be a six to nine second delay, Then it will send the "Continuous Memory" Codes... (the ones it stored in memory during the last 40 trips to the store.)

Using the same method... 2 sec delay between digits, and 4 sec delay between codes.

That is crazyness. Thank you.

 

[spraymonkey]

Sorry a bit technical but its not as hard as it seems i used a paper clip in my 93 grand prix with an obd1 the hardest part is making sure you pay attention to the CEL blinks.

 

[spraymonkey]

Heres an example to help im not familair withb the codes for an obd1 on a ford so bare with me lol.

( flash, flash, 2sec delay flash, flash, flash. 6sec delay, flash, 2sec delay, flash, flash, flash, 2 sec delay, flash flash.)

The first code would be 13, the second would be 132. Again this is an example you may only have 1 code or multiple but just write them down and wait for it to loop back to the first and double check. Good luck

 

[mobile madness]

Heres an example to help im not familair withb the codes for an obd1 on a ford so bare with me lol.

( flash, flash, 2sec delay flash, flash, flash. 6sec delay, flash, 2sec delay, flash, flash, flash, 2 sec delay, flash flash.)

The first code would be 13, the second would be 132. Again this is an example you may only have 1 code or multiple but just write them down and wait for it to loop back to the first and double check. Good luck

Oh I meant crazy awsesome. I went and looked under my hood and the only lose plug was on the core support and it had a cap on the end. I knew about the paper clip trick when my budddies 87 s10 was throwin codes.I just didn't know where my plug was. I looked everywhere for it and in the chilton manual.