If your "Check Engine" light is on, you can check the trouble codes by turning the key on and off rapidly. The sequence is "on, off, on, off, then on" The codes will be displayed by the check engine light. It will blink out the first digit, pause, then blink out the second digit. All trouble codes have two digits. So code 23 would be displayed as two blinks, a pause, then 3 blinks. If there is more than one code, codes will be displayed in numerical order (code 15 would be displayed before code 34). Code 55 will be flash when all trouble codes have been displayed. It is not a trouble code.

Codes:
11 No Crank Speed sensor signal during cranking
12 Battery connection disturbed within the last 50 starts
15 No signal from VSS (Auto or Cruise Control equipped only)
22 Coolant temp sensor shorted or open (Auto only)
23 Air temp sensor shorted or open
24 TPS shorted or open (Auto only)
33 A/C clutch relay shorted or open
34 Cruise control shorted or open (cruise control equipped only)
41 Generator field not switching properly
42 ASD relay (charging circuit supply) shorted or open, or no ASD voltage at PCM
45 OD solenoid shorted or open (Auto only)
46 Charging system voltage too high
47 Charging system voltage too low
53 Internal PCM failure
62 same
63 same

 

are these all the possible codes?
and also im getting codes out of numerical sequence.
12, 45, 22, 24


and aside from 12, all the codes say auto only but i have a manual. what would that mean?

 

Alot of times you will get codes cause you dont have those options. The computer in these old trucks is not intellegent enough to know the difference.

 

This is some great information, I had no idea our trucks computers were capable of trouble shooting. Thanks a lot Faith!

 

Ya, I have a few out of sequence too. like 12, 41, 24... even though I have a POT for O/D.

 

I believe the codes are shown in the order that they occurred -

12 - you unhooked the battery
41 - your alt field didn't switch on/off properly
24 - your TPS isn't responding --- usually when you have a pot the PCM expects minimum volts when the truck is started but the pot gives different reading..

You need a DRB II to reset the codes - or is it the ODB ?? Anyway, it's the older version

 

OBD I compatible reader would be needed.

 

I hope this makes it into the sticky!!!!! lol

 

Do you have an auto ECM instead of a manual ECM?

 

sorry im not sure
how do you tell?

 

maybe your truck was converted from auto to manual and the ECM remained the auto ECM. That's how my truck is and I bet you a lot of converted trucks are too.

 

You will have to run the part number to find out.