'02 KJ code mystery.

[KJCrazy]

My daughter's '02 KJ 3.7L V6, around 125K on the clock, newly rebuilt top-end, is sending me on a goose chase.

I installed a new PCM after the rebuild. A couple days ago, I took it for a test drive and got P0205, P0138, and P0158. The O2 sensor codes have disappeared, which I thought they would after the initial run.

Today, I reset the PCM and drove it for about an hour. I kept it running inspite of it's wanting to stall when I let off the gas to slow down for an intersection.

I parked it back in the yard and checked the CEL. Today, no P0205.

Today, I got P0201 and P0202. That's a first. I haven't done anything to the injectors or the injector circuits. AND, it only sets a code after the engine comes up to operating temp. Until then, it runs smooth like a brand new engine.

As always, any help is greatly appreciated and needed.

 

[Dave]

Bumped it for you so someone that can help might see it.

Dave

 

[KJCrazy]

I just went outside and started it up. I let idle for 10 minutes or so. It sat there running smoothly until I shut it off.

The PCM set a P0206 code along with P0202 and P0201 from yesterday.:favorites68:

How is it running smoothly but setting codes?:Frustrated::emotions122:

 

[LibertyTC]

Brine New PCM.. where did you get it from & was it pre-programmed?
Well those 3 codes are for injector control circuit, cyl 1-2-6.
Would be great to have a look at live data on a good scanner to see what the injector pulse is doing. Double check for no leaks & electrical connectors/wiring.
Did you install new o-rings into each injector?
I also would try a good fuel cleaner like Bardahl or Chevron Techron concentrate in a heavy dose with a good hwy run, to clean things out.
Low rpm & wanting to stall says check the fuel pressure and the IAC (intake air control)
often get dirty,& mainly controls the idle & it gets carboned up, so remove it, clean into the TB port etc...
see post #10.. http://www.jeepkj.com/forum/f196/idle-air-control-no-screws-44826/

 

[KJCrazy]

Brine New PCM.. where did you get it from & was it pre-programmed?
Well those 3 codes are for injector control circuit, cyl 1-2-6.
Would be great to have a look at live data on a good scanner to see what the injector pulse is doing. Double check for no leaks & electrical connectors/wiring.
Did you install new o-rings into each injector?
I also would try a good fuel cleaner like Bardahl or Chevron Techron concentrate in a heavy dose with a good hwy run, to clean things out.
Low rpm & wanting to stall says check the fuel pressure and the IAC (intake air control)
often get dirty,& mainly controls the idle & it gets carboned up, so remove it, clean into the TB port etc...
see post #10.. http://www.jeepkj.com/forum/f196/idle-air-control-no-screws-44826/

The PCM was preprogrammed to her VIN, mileage, and part number. It's my third purchase from a reputable company. I've had zero trouble from their modules in the past.

Yes, I installed new O-rings on the injectors during the rebuilding process.

I did remove and clean her IAC, but I didn't think to clean the port as well. I'll do that tomorrow.

 

[KJCrazy]

I just found this from a factory service manual, or otherwise known as a TSB.:

Multiple injector circuit codes. MIL on, no noticeable driveability problems. May have code P0121 - TPS voltage does not agree with MAP. Possible codes P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208
System:
Emissions/PCM/Fuel
Codes:
P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208
Problem:
The PCM software falsely sets injector circuit codes when there is really no problem with the injectors. The problem is voltage spikes from the Throttle Position Sensor.
Test & Fix:
Throttle Position Sensor (TPS) voltage spikes greater than 0.02 volts trigger these false codes. Theoretically, this could be caused by an intermittent ground or other wiring connection. However in actual practice it is almost always a problem with the TPS itself. Due to the nature of this problem there is no conclusive way to test the TPS or the TPS circuit. If there are multiple injector circuit codes with no misfire, replace the TPS and clear the codes.

 

[ltd02]

Is the current TPS original? Use a Mopar one if replacing.

 

[KJCrazy]

Is the current TPS original? Use a Mopar one if replacing.

I'm assuming that it is original. I have had good luck with BWD parts. They're listed as OEM.

I'm NOT cheaping out here, and I know our Jeeps need sensors that are MOPAR specific....

I've done TONS of research and believe parts are made by the same manufacturer, no matter the part number.

I've been running a BWD TPS in my 2000 WJ 4.0l i6 and have zero issues with it.

 

[KJCrazy]

Is the current TPS original? Use a Mopar one if replacing.

I tried the BWD TPS from AA just now and a lot of things improved. No stalling, no P020x codes. But, as I was pulling back in the driveway, it shut off and now has the dreaded P0340 code.

Could the BWD TPS somehow damaged my cam position sensor?

 

[KJCrazy]

After sitting for a day or two, the KJ will not start. The last time it ran it set a P0340 code. No signal from the cam sensor to the PCM. That was Friday.

I pulled the negative cable off for the weekend and put it back on a little bit ago. Now, it just turns over but won't start.

 

[ltd02]

After sitting for a day or two, the KJ will not start. The last time it ran it set a P0340 code. No signal from the cam sensor to the PCM. That was Friday.

I pulled the negative cable off for the weekend and put it back on a little bit ago. Now, it just turns over but won't start.

Bad cam sensor can cause a no start. Can also cause misfires that can get worse when it warms up. Is the connector okay? Has it ever been replaced?

 

[KJCrazy]

Bad cam sensor can cause a no start. Can also cause misfires that can get worse when it warms up. Is the connector okay? Has it ever been replaced?

It's never been replaced. It's the original. It's just odd to me that it picked NOW to go bad. Is it normal to have to replace one after 125K?

 

[tjkj2002]

It's never been replaced. It's the original. It's just odd to me that it picked NOW to go bad. Is it normal to have to replace one after 125K?

Like anything else it can last 1 mile or 1 million miles.

Oh and stick with the actual MOPAR part,does not matter if you get the part from the manufacturer as that one will not be the same.The actual OE part is subjected to stricter QC standards then there own named part.

Just a note the engine can start with a bad cam sensor,it's the crank sensor it needs to start and Chrysler's are famous for not being able to actually tell the difference between the cam or crank sensor when it spits out a code like P0340 or P0320.Best to replace both with MOPAR parts.


Sounds like a classic PCM problem,never get a PCM from anywhere besides the dealership,don't care how good of a rep a place has.

 

[KJCrazy]

Like anything else it can last 1 mile or 1 million miles.

Oh and stick with the actual MOPAR part,does not matter if you get the part from the manufacturer as that one will not be the same.The actual OE part is subjected to stricter QC standards then there own named part.

Just a note the engine can start with a bad cam sensor,it's the crank sensor it needs to start and Chrysler's are famous for not being able to actually tell the difference between the cam or crank sensor when it spits out a code like P0340 or P0320.Best to replace both with MOPAR parts.

I went to the Jeep dealer today and got a new Mopar TPS and cam sensor. The parts guy said there are literally NO Mopar crank sensors available anywhere, and he's right. None on ebay or rockauto. NONE.

I picked up a BWD crank sensor and we'll see how that goes. I installed the TPS and cam sensors today and it is still not starting and now has the P0340 back again, so now I know it's a bad crank sensor.

Thanks for all the help, guys!

 

[Billwill]

I would check out that P0340 code...maybe disconnect the battery and re-plug the PCM connectors a few times and check the connection to the Cam Sensor.

Is the fuel pump running and is the fuel filter clean? You can swap over the fuel pump relay with an identical one next to it. If you still cannot hear the pump running remove the fuel pump relay and jumper female pins 30 and 87 inside the relay socket which would force power to go to the fuel pump.

While you are there...swap over the ASD Relay with an identical one.

Does your KJ have the SKIS anti theft installed? If it is installed then the early KJs have an amber "key" icon light up for a few seconds when ignition is turned ON. If the icon does not go out after a few seconds but flashes at you or stays ON all the time then there is a SKIS chipped key issue.