DTC's
 

Forgot to ask about DTC's. With everything connected, what are the codes? Trying to make sense of the meter measurements with what failures the PCM has detected.

:cheers:

Splice S133
 

Here's the scheme for the 2/1 O2 sensor. Note that the signal return (likely with the 2.5V pull-up bias) is the exact same pin (C2/32) as the 1/1 sensor -- via the splice S133, wire K902, and connector C2/32.

Odd how they make you look at both schemes to figure out what that splice is for. This little detail may figure prominently when ohming out the wiring.
:cheers:

https://cimg8.ibsrv.net/gimg/www.jk-...2632785a55.jpg

I reconnected everything and ran the Jeep for about 30 miles. The codes I have is PO155, 0032, 0052, and 0155 again I had a P0300 but that reset.

I looked up the numbering for the black orange connector. I apologize I may of been reading the wrong points because the reading I have now are different from this morning. C32 is OL, 18 is 0 Ohms to ground.
Between 18 and 32 OL. 18 and 32 wring out to separate pins on the O2 sensor connector.

I reconnected everything and ran the Jeep for about 30 miles. The codes I have is PO155, 0032, 0052, and 0155 again I had a P0300 but that reset.

I looked up the numbering for the black orange connector. I apologize I may of been reading the wrong points because the reading I have now are different from this morning. C32 is OL, 18 is 0 Ohms to ground.
Between 18 and 32 OL. 18 and 32 wring out to separate pins on the O2 sensor connector.

I don’t know if just disconnecting the sensors and reconnecting them changed anything but now from the codes it looks like it is just the 1-1 and 2-1 sensors that are having and issue with the heater side. Im looking into a better scanner or a cheap computer.

G104 ground
 

Look for the ground G104 in the schematic and see if it has a high resistance -- anything over a couple ohms is too high, and it could be an intermittent bad connection. This single item would cause all the codes listed.

More later, but figured you might be working on it now. :cheers:

Have a feeling you're getting close to a solution. More pin-outs...
https://cimg4.ibsrv.net/gimg/www.jk-...8005d24b10.jpg


As mentioned prior, still have a strong suspicion that G104 has high resistance. Note how both 1/1 and 2/1 sensors share this ground, and a high resistance ground G104 will cause all the codes mentioned. Also, the heater elements are supposed to have 3-30 ohms at 70F temperature when checked with a meter.

Here the code definitions:

P0032 O2 1/1 heater ckt high
P0052 O2 2/1 heater ckt high
Basically these codes mean that the PCM pin feeding the relevant O2 heater circuit has higher voltage than expected -- for example there isn't ant current draw from the heater element within the O2 sensor.
P0135 O2 1/1 heater ckt performance
P0155 O2 2/1 heater ckt performance

More on G104
 

Looks like G104 is one of the infamous engine grounds (O2 heaters, EGR, A/C clutch), the other is G101 (back to the battery, sized for the starter motor). All the O2 heater ckts are tied to it. It is located on the passenger side of the block, toward the rear, near the knock sensor. It is across from the cat. Taking it off completely is a big job, but I think a thin open-end wrench can be used to tighten it. Maybe grind a wrench thinner to get in there -- It's a double nut affair if I remember correctly, the outer holding the heat shield and the inner holding the ring lugs to the block.

Don't know how all the devices that use G104 get connected. Could be the wiring between G104 and the 1/1 and 2/1 sensors connector pin 2 heater ground is open/high resistance. However, it's interesting that the 2/1 and 2/2 O2 sensors don't have the heater high codes (yet), but it sounds like they did prior -- If so that would be even more convincing that G104 is the issue.

Here's where G104 and G101 are located... It's bedtime here, good luck tomorrow :cheers:

https://cimg4.ibsrv.net/gimg/www.jk-...5976191926.jpg

I appreciate all the help Mr. T, I traced the wiring out to the same ground lug I ran the negative battery to. Pretty much exactly like you said and in the picture. I bent the heat shield and removed all three ground connectors cleaned them up re-installed everything, erased the codes and still had the issue. I reterminated the O2 wires and reconnected everything, cleared the codes, still had the same issue. I pulled the terminal with O2 sensors wires and ran it to the ground terminal Where the hood is grounded. Cleared the codes and no engine light.
Could it of been the ground wire I ran from the battery that was causing the issue? I don’t see how though.

Again I appreciate all the help and you taking the time to look things up and impart some knowledge to me.

Good troubleshooting move by wiring the O2 heater grounds to where the hood is grounded. You've proven (the original) G104 was a bad connection back to battery neg, likely an intermittent problem that won't easily show up with ohm-ing it. BTW- one way to ohm suspect intermittent wiring is wiggling the wires, especially at connection points, while measuring resistance on the lowest scale.

For proper operation, G104 has to make it all the way back to the battery negative with a solid low resistance connection, and since the connection at the block where you bent the heat shield for access has been cleaned and tightened -- I think it might be that the G101 large wire on the same bolt going from the engine block (you already cleaned that end) to the battery neg has a bad connection. It could be a loose crimp, corrosion, or even the wires have a break inside the insulation (from vibration maybe) -- Check the top end first since it's easier. Some of the hardest problems to troubleshoot are intermittent wiring, but you have really narrowed it down to just that section of wiring (essentially G101) replaced to get it functioning with no codes.

Regarding the extra ground wire added earlier: Where exactly is the added ground wire connected at both ends? This wire should have provided another parallel path from the engine block to battery neg, keeping this issue from happening even if the G101 wire is bad. It doesn't quite make sense (yet) why the starting issue was apparently resolved by adding this redundant ground but the O2 sensor heaters still can't get a good path back to battery neg.

Hope this helps narrow it down further! :cheers: