cjfrigo

Alright so my friend looked around finally he took some wire and grounded pin 4and 5 both grounds are not grounded. How should he go about fixing this ?

Faulty codes are a pcm code and tcm something about a reflash and buzz circuite

I know I might be annoying you but I'm just trying to fix it myself rather than take it to a dealer I really appreciate all your help

CCKen

The ground point for 4 & 5 oon the DLC are at the oil dipstick tube bracket stud. See pic.

I have no idea what this means: "reflash and buzz circuite".

cjfrigo

Alright ill look to make sure they are grounded good. I believe he said they where grounded he said about maybe they are cut somewhere .

cjfrigo

They are connected there. Guess I either need to start following wires or try AMD figure out how to re wire the grounds

CCKen

Before rewiring, do this:

1. Verify the pin sockets (4 & 5) on the DLC are not corroded or enlarged. Corrosion may have a gray or black appearance.

2. Do a preliminary check of the DLC pin sockets 4 & 5 to chassis ground using a digital Ohmmeter. Probe each pin socket (4 & 5) to chassis ground, like the nuts that hold the gas pedal bracket. Do not shove the meter probe into the pin socket. You should read continuity with no more that 5.0 Ohms resistance.

3. Remove the DLC ground wires from the stud and make sure the ring terminals are not corroded. Sandpaper/clean as required. Reattach.

4. Using a digital Ohmmeter, check for an open or high resistance from pins 4 and 5 on the DLC to the ring terminals at the ground stud. Pin 4 wire is Black, pin 5 is Black/Tan tracer. You will need to use a jumper wire to reach from the DLC area to the ground stud area. The resistance should not be over 5.0 Ohms.

cjfrigo

So I checked the grounds on the block even cleaned them. Tested the resistance on the ones on the block there grounded good still no ground coming out of pin 4 and 5 and I also found no corrosion on them

cjfrigo

days work
so i checked the grounds on the block they are good. checked pin 4 and 5 still no ground.

i have read people having trouble with the crank sensor. so we unhooked the crank sensor. still no ground at the pins. my friends scanner is self powered so it didnt need the grounds to work. with the crank unhooked we pulled codes p1698 and p1694. once we hooked it back up scanner lost communication and dash diplayed no bus.

idk if its the crank sensor because my jeep still runs ?

cjfrigo

Checked the ground to the pcm from the block both measure around 5. Ohms replaced the crank and have no change. Still says no bus while crank is plugged in. Im guessing all thats left is to clean the connector to the speedo?

Rocky Mountain High

My 96 Cherokee Sport will not hookup to the OBD2 either. The CEL came on and when I tried to hookup my scanner to the OBD port it would not communicate. But when I disconnected the TCM, located in the knee kick panel on the passenger side, it hooked up fine and a P0420 code also. I know the code is the CAT and I will take care of that ASAP, but the Jeep shifts fine. CCKen posted #15 that (there's a fault in the TCM that has corrupted its SCI Transmit Circuit). Why? I disconnected the TCM and the Jeep wouldn't shift automatically only manually through the ranges except for reverse, and it would work in reverse. Does the TCM need to be replaced just to get the OBD to hookup? A fault in the TCM?

J4by

Mine doesn't scan either, must be a common thing like no bus. Lol

Manelishi

Add another one that won't communicate. The tally of ones that don't communicate vs ones that get solved is staggering. All I have to honestly add is after not communicating with my autel ultra and confirming powers n grounds I plugged in an old zr13 and it communicated but was slower LD than normal . It's a 2000 wrangler with no issues other than communicating with at least one scanner. Beings I'm retired , it's my neighbors jeep he bought for his daughters first car and clearly a definitive answer is needed other than I'm tired of people saying these jeeps that don't communicate, don't communicate. If I'm successful following some of the real advice on here I'll post what I found. Clearly there is an issue beings this is the first no com for the ultra

dirkexc

My 99 XJ does not communicate either. My mechanic had a terrible time
getting it to communicate last year and I have to do another smog this year, thanks California,
and I can not get it to communicate with my scan tool today. the second and third ground pins
in the top row work fine with the positive connected to the bottom row far right positive pin, but
when I turn the key on the connection between the second position ground and 12 v bottom pin the volts drop
to 3 volts. Looks like I have some work to do. Ken comments helped me get to this point. His posts
are very helpful.
If I find my power drop issue I will post up,