I just figured out how to get computer codes to display on my 94 Jeep.

Pretty cool. I cycled the key on/off twice then turned it to the on position without cranking the engine. The Check engine light started blinking out code. Can anyone tell me what they mean and how they might affect the shifting on my Jeep?

Blink, pause, blink, blink, pause, blink, blink, pause, blink, pause, 5 blinks, pause five blinks.

Any help would be great.

 

The first one is 12, battery was disconnected at some point within the last 50 starts, nothing to worry about. The second one is 21, give me a minute I'll look it up and let u know what that means. The last one is 55, end of codes list, just saying your codes are dine.

 

http://orj4x4.com/showthread.php?116...Grand-Cherokee)

 

That's the whole list for you. 21 is the one you want to read.

 

I just went thru this like 3 days when mine was on, luckily $36 fixed my problem.

 

The Haynes repair manual has all that stuff in it and is cheap. I buy one for every vehicle I own.

 

So I took a video to make sure I am doing this correctly. http://youtu.be/IssRKwc0LR4

This is the code I got, but I am not sure what it means. Can anyone translate it into what I need to replace/clean/duct tape back in place or shoot?

21 Upstream oxygen sensor response slower than minimum required switching frequency. Upstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor input voltage maintained above the normal operating range. Oxygen sensor voltage too low, tested after cold start. (Upstream or Downstream) Left oxygen sensor input voltage maintained above the normal operating temperature.

 

You should put a scan tool on it and see what it says. My guess is the wires, connectors, or the 02 sensors themselves are at fault.