2001 Grand CherokeeWorking on vehicle.Throwing a few codesRun smooth at stsrt up. Abo

[dlmrun2002]

Cleared codes and reset PCM with batt disconnect and ignition on for 30 seconds. I will re-check TPS install but it went in flush mounted. Didn't have to rotate TPS clockwise to get it in. It might be off. Not sure. TPS looks like old one too. Will give TPS wires a wiggle. Got a transmission relay from NAPA store but having a hard time finding a listing for the actual transmission control relay. Most places don't list it. But it is the same as my ASD relay ( I think) in my Jeep ( numbers Match-Siemens) which I see listings for. Not sure if the Napa is up to spec. Hard to tell.
••Thanks••

dlm ny country

 

[JPNinPA]

Not sure what else to tell you. You corrected the O2 codes and replaced the TPS. Correct? If your scan info is the same as before in the video, the long term fuel trims looked a bit high suggesting a vac leak or bad fuel pump blockage in fuel delivery. And your bank 1 sensor 2 seems to switch as fast as sensor 1 suggesting you have a bad CAT in bank 1.
I'd watch to see if anything is jumping while shuddering.

Try this for reset. Not sure how far back in model years it works.

Jeep Electronic Control Unit Reset

The following procedure will allow you to reset the memory and allow the computer to 're-learn' how to drive by adjusting to the drivers habits and the vehicles modifications.


1. Disconnect the battery by removing the positive battery cable. Remember, the positive battery cable.

2. Ground the positive cable to the negative cable for 30 seconds to erase the electric charge in the capacitors.

3. Reconnect the positive cable to the battery.

4. Turn the key to on but do not start.

5. Turn the headlights on.

6. Turn the headlights off.

7. Turn the key off.


Regards,
JPNinPA

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[dlmrun2002]

Will try..Took out newly installed TPS and found out I forgot the seal that goes with is. However it appears it was in right. Put new seal in when re-installing TPS. There really wasn't a need to turn clockwise. It slid right in flush mounted. like the original one I replaced. There is NO Schrader valve on my fuel rail.. just the little round attachment that helps regulate fuel pressure on the rail. TPS % reads 16.3 constant with new seal in. Still getting P0136 code which is the sensor I replaced with a Bosch. All my transmission codes are back P0743,P0753,P1765. Also still getting P1495, P0136 plus 14---ABS cluster malfunction.. WTF?

dlm ny country

the photo is not my fuel rail just showing the fuel rail round gizmo

 

[dlmrun2002]

Yeah none off that worked. For some reasonI'm getting a code 14 ABS cluster malfunction and my code reader won't let me clear it. Says module is busy. Recycled code reader a few time...?$?$?$?$?$

dlm ny country

 

[JPNinPA]

The port usually is near the front 2nd cylinder pointed away from the engine.


Regards,
JPNinPA

Sent using TapTalk

 

[dlmrun2002]

Nothing there. Gonna pull power distribution block and see if the mice ate underneath it. Also my evaporation pump P1495 is ticking a bit. Gonna see if I can give it a look/see/clean?? maybe.

dlm ny country

 

[JPNinPA]

I know i asked and you said you replaced the battery but I'm going to ask again. Are you sure your power and ground cables are good low resistance? And the connections at the battery and the opposite ends engine and chassis are clean/shiny low res contacts?

I had issues with many codes, rough running and not starting because of a poor ground.

On Second thought. This only happens in closed loop that tends to indicate a sensor.


JPNinPA
Using Jeepz.com app

 

[dlmrun2002]

Possible break through. After exercising every avenue I could I actually found that I can eliminate the engine stumble that comes after start up (open loop). I found by using my Actron code reader when I do a evaporation system test I can eliminate the stumble. Also if I activate the Actron evaporation system test in Open loop( Before stumble comes) I won't get the stumble. I can actually feel the actuator on the pump move when I do the Actron evaporation system test. So that leaves me to believe the leak detection pump is working but not getting it signal to work. Does the vapor canister purge valve solenoid give the signal to the leak detection pump? The Valve solenoid is clicking too when I go to closed loop and if I hit Actron evaporation system test it stops clicking plus I can feel the evaporative pump click, thus good idle. . Oddly enough this fixed all my other OBD2 codes, transmission,o2 sensors..Kinda crazy but I hope that is it.

dlm ny country

 

[JPNinPA]

Well all I could say is to go through the system looking for leaks or proper function.
It is strange that it would cause trans codes. Shorts or open? System seeking ground and completes a circuit when you activate the test???


JPNinPA
Using Jeepz.com app

 

[dlmrun2002]

Yeah I thought it was strange too. Plus an ABS code. I did a pretty thorough inspection on hoses this week. Also used a ton of carb cleaner. Live data still shows my TPS at 15% but the Jeep seems good once I send a signal from the Actron code reader. Not sure of the signal (hot or ground) the Actron is sending but it is works. Think I'll pick up a new Evap Solenoid.

dlm ny country

 

[dlmrun2002]

Well that a didn't work. I didn't think it would but it was worth a shot. If I had a pinout for the Evap Pump connector ( 3 wires) and the Evaporation Solenoid (2 wires) That might help. Really a full evaporation schematic would help. I'm suspecting broken wire/connection too at this pint ( subject to change), possible lack of ground. The Evaporation solenoid was showing consistent 12 volts when Jeep goes into closed loop.

dlm ny country

 

[dlmrun2002]

Did some more testing on the Evaporation Pump connectors.On the 3 Pin connector, the middle pin showing (green and white wire that connects to PCM )shows good steady 13.6 volts in open loop. When going to closed the volts drop to 11- 12 volts jumping around a bit with the rough idle which throws a code. If I use the Actron Code reader to run evaporation test when system goes to closed loop the voltages drops down to basically 0 volts. Small oscillation to ( .2 volts). Not sure if the voltage drop is related to Pump not working or not. Looking for any feedback.

dlm ny country

 

[dlmrun2002]

More testing. More no answers. So I removed my leak detection pump, disconnected the hose going to filter and hose to charcoal box and vacuum line to manifold. Disconnected 3 wire connector. Nothing change. No leak detection codes. And engine stumble clears as soon as I hit Evap System test on my Actron code reader. Also had a chance to exercise the connectors on the PCM. Connectors looked clean but doesn't hurt to exercise them. I am wondering if there might be a problem with the PCM at this point. This is driving me freakin crazy.

dlm ny country

 

[dlmrun2002]

Time to wave the white Flag. After replacing the leak evaporation pump I still got the same results. It was worth a shot and Autozone lets you return electrical parts.. yeah for that. I will bringing back and get my money back ($128)
I've swapped an o2 sensor, TPS, transmission module relay, Evap solenoid. Cleaned throttle body and IAC. I've cleaned all grounds, exercised all PCM connections. Checked for continuity on Evap detection pump wire going back to PCM ( wh/drk green wire). It's good. Checked continuity to Evap Solenoid from PCM ( Pk/Bl). It's good. If I let engine start up and run till the stumble comes in I still get the same random codes. P1495, P0743 and P0136. If I start up and hit "Evap Sytem TesT" on my ACtron code reader before stumble..no codes, car runs fine. Took it out and put a few miles on it and added some fresh gas since the car has been sitting for over a year. Car ran fine and shifted fine on the road. I do know the wh/ dark green wire going form the Evap Pump to the PCM goes from13.8 volts in open loop. If I hit Actron code reader "Evap Sytem TesT", voltage goes to 0 ( ground) If I don't hit the Actron code reader, after car goes closed loop the voltages drops a bit ( 11v- 12v) but doesn't go to 0v( ground).Thus the car stumble...maybe. Not sure why but I think the PCM should do the switching and it is not happening. That is my sad story. Will post if I get hit by lightning. Time to replace dread CPS on my 2002 bmw e46 325xit wagon. It's gonna be hair and teeth all over the place on that one.

dlm ny country

 

[JPNinPA]

Don't know what to say. Here is a decent vid on evap systems.

Regards,
JPNinPA

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[dlmrun2002]

Yeah I've seen that video and his other one( the cursing man !!! ). Two thought's that I have are.. 1- Possible the evaporation solenoid or the evaporation pump that I swapped in ( new parts) might have been defective. The other thought is there is another sensor that is throwing things off that I have no clue about. Outside of that and possible faulty PCM, I'm stumped. I am also thinking how I can trick the system to send a ground pulse to the evaporation pump connector via relays. The theory would make it rest at ground ..kind of the way door locks work. I've done it on install on a 1974 BMW when I put in door lock system with a remote.

dlm ny country

 

[JPNinPA]

Well the purge solenoid goes to the intake and is normally closed. As a test could you temporarily pull that vac hose and plug the intake port keeping it closed?

That will rule out the evap system???
If it still stumbles you need to find out what that program does. Perhaps it forces the system to run open loop.
Then it ignores the sensors...


JPNinPA
Using Jeepz.com app

 

[dlmrun2002]

I spoke to Tech at Actron code reader looking for info on their test signal using the Actron code reader. According to the tech the Actron code reader doesn't actually have software that does does the test, they just tell the PCM to run it's own test. So they really had no answer for me. I guess the Jeep PCM in open loop runs the evaporation test system to check for leaks and then goes on to closed loop. I don't know what the Jeep proprietary test does but run pump to see its manner to determine if there is a leak( big or small) based on it's pumping frequency ( square wave modulation). Who knows?

dlm ny country

 

[JPNinPA]

At a minimum I'd put a vac gage on the intake to see what vac levels you get. If something is opening when it shouldn't or not when it should you will see it in the vac level. It should be 12-14 in of Hg.

And if you didn't know many stores like AZ or O'rielly's loan the tools.


Regards,
JPNinPA

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[JPNinPA]

Ever revisit this?



JPNinPA
Using Jeepz.com app