New PCM plugs and wires and upper and lower bank o2sensors at 75000 miles.Replaced o2 sensor p0132 at 82000 miles check engine code comes back after clearing
New PCM plugs and wires? hun?
new harness ,why? in a fire or wreck? running off road?
or did you mean, new PCM, new spark wires, and all new 02s sensors' It wont be a bad PCM , sorry, 99% are good.
P0132
the PCM never lies. it measure this and does a test and if it fails there is a circuit fault.
the why to understand, DTCs (have a FSM factory serv. manual)
and read how the test works. or do the tests it tells you do to
to discover true cause)
i have this car v6 3.8L: and 6speed and the FSM, book.
verbatim.
O2 SENSOR 1/1 CIRCUIT HIGH
1/1 means bank 1 , front sensor (upsteam)
bank one means right bank, cylinder 1 side.
what does HIGH mean?
what is not clear is which side is failing, heater or CELL
this test is the CELL pin (oxy out)
pin 4.
the test (called a monitor) finds that pin 4 is stuck at 5v.
the o2 must be 0 to 1volt at all times.
if stuck at 5vdc then the ground is open to CELL pin 3 (wire cut)
or the 02 sensors is bad. (open)
do you know how to back probe? a skill that is must for all modern cars. use needles with your meter. (DMM) (leather needles work in a pinch sold at walfart for 1buck) needle probes are 10x better
key on and back probe pin 4, if at 5vdc or more(or near) it's wrong.
btw page 2891 shows what to do in the FSM. yah 7000 pages.
I think this pin floats to 5v if the wire is cut.
fail 2 is that pin 4 is shorted to voltage ,well , the heater runs off
of 12v and all cars (bad service) the 2 wires melt and short.
here ill list all 4 pins (key on)
1- 12v heater.
2- ground
3 - ecu quite ground to 02 (cell minus)
4- CELL + out (this is the oxy signal)
pin 4 must not be at 5v or 12v, but 0 to 1 volts.
at key on or running.
one more FSM quote
Measure the voltage in reference to ground, not the (K902) O2 Return Upstream circuit.
that means pin 3 to 4, is measured for best accuracy
but 5vdc or 12vdc is gross wrong .
if the o2 is new (is)
then this quote covers most fails on most cars
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact
in the Oxygen Sensor and Powertrain Control Module connectors.
here is the wiring.
if you need more photos full size or more tests.
or have questions, ask, i'm a retired ET, (controls systems , PLCs +)
see FSM here
on CD (best of best)
https://www.techauthority.com/en-US/Pages/FacetSearchResults.aspx?make=Jeep&year=2008&model=WRANGLER+UNLIMITED+RUBICON+4X4&engine=3.8L+V6+%28SMPI%29&producttype=Service+Manuals&ptCatId=3083
Testimonial: "Thanks for the help. Do you have any recommendations for a voltage tester? Around 75,000 miles the check engine light came on for all 4 o2 sensors so I replaced them cleared the codes and the light came back on. The dealership said the PCM was bad and replaced it. The jeep was running fine when I dropped it off at the jeep dealer a few miles after I picked up it started running bad had the plugs and spark plug wires tested and a few were bad. I replaced them and I ran just fine. At 82,000 mile the gas cap light came on and next both upper o2 sensors I replaced both and only the right side code went away. Thanks so much for your help!"
the PCM is not bad, how can the 4 inputs to and PCM all dies? they are well protected too. id need all DTCS thrown. and way is your jeep guy not finging it? he surely has the tools. The gas cap was loose. forget that. you said all 4 failed and didnt tell the DTC, there are 26 DTC for 02, which ones fail? and did it fail parked in the driveway, runnng? if it did, you can measure the voltages, parked, and find the cause, in fact with a scan tool see it fail parked idling, and find it with the voltmeter, any meter even a 10 buck walmart meter works. try going to a real ASE shop with fully trained mechanics, that can check out a simple electric failure. so you have bad wiring, not a bad 02s set, not a bad ECU, only a simple open connection. but to find it the tech would first check all connectors, from the 02 to the ECU, and i bet that has yet to be done, all not just the 2 ends. That one stuck high error is an open on the pins 3 or 4.(02) back. for sure,l ill check my FSM harness wiring page at the end of the FSM now , to see if there are suprises.
are you a hands on guy,. or just want to out guess the mech, or just want the PCM to tell you where to look? if hand one, you can in fact check every inch of that harness end to end. looking for damage. and will find it. if you had. throwning in a new ECU that must have been expensive. Id have back probed 3 and 4 pins at the ECU (diffr. # there) and seen 5v there. and known that the ECU was telling the truth. save that wild guess.
if termination S133 fails both front sensors fail.
the error DTC P0132 nothing at all to do with the engine or hot it runs, (sure is a victim) but this error is caused by a catastophic error in the wiring, I will now say what the ECU saw, at 132, the ECU monitors o2-B1S1, pin 3, all the time. in fact over 20 times a second, and if it see legal levels there it sets AFR (fuel mix)using that reading but if the reading is Illegal (say 5vdc (yours was) then it sets P0132, imgine looking at your , house thermometer, and seeing 1000 degrees F, would you buy a new furnace(silly huh) or fix the termometer. sure the later. in this case its and electronc sensor that is DISCONNECTED , when that happens it floats to the illegal 5vdc, of the ECU term, resistors, called pull ups; (computer classes real) so the ECU knows it at 5v and reported it, and the only cause is bad connections there, its not the 02 its new. its not both PCM, never was. so its a bad harness, or wires,or connectors to those 2 pins. 3 and 4.
my cheap FSM does not have the physical harness drawings. that show every inch of the harness. but one can just trace the harness, from end to end, inspecting each inch of it, and every connector on the way for damage. that is how we do it. do you have a scan tool or is this all autozoned scans, word of mouth? (the lil. horror of that)
you never disclosed the new oxygen sensors makers name or part numbers so i cant look up if they are even correct. i bet the old sensors were still good. mine are. just hit 60k this week. now lets prove its not the o2, step by step, on 1/1 bank1, sensor 1., take my trusty 10 buck meter, set it to 20vdc scale, and then connect the black lead to 02 pin 3, (back probed) then red lead to pin 4, i start car, and it reads 5vdc. the sensor is dead open, lets say its 0v. oops, the ECU pin C2-31 is at 5vdc, that means this wire. is open. dark blu-lightblue , Nodal analysis. so now pretend the pin 4 at the 02 is 5vdc and pin 4 is too, at 5v, that means the ground is open, on THIS wire, I go to ECU C2-pin32 and its at 0v, so the wire brn-drk-green is open. from ECu to 02. what more do you need but that? the wire is open, (could be corroded damaged connector) or melted 02 wires, did you look for wire damage yet, 02s sometimes are changes out buy goons that dont put them back in the clamps and then they hit exhaust, and they melt, like the #1 cause of all 02 errors, or engine pull damage. or the like.
If it is truly intermittant? that is you have a scan tool and you cant see the o2 B1S1 readings super high, stuck high,? then you must find it by inspection. if you do see it , and its stuck high with the scan tool and you are parked, then you can in fact find it with a $10 voltmeter, for sure. it will tell you which of th 2 wires are cut. sure will , every time.
just 4 readings, one at the 4 points, of the 2 wire feed to O2. 2 at ECU , 2 checks at 02. and you know which wire is cut. for sure.
if you need a video of a old ASE tech doing this we have it.
Thanks again I started with the wiring harness and found a broken wire blue with a light blue stripe so I fix it and the check engine light is now out no codes I didn't look to see what the wire went to but it didn't go to the o2 sensor I guess it has something to do with the problem. Thanks
dark blue-light blue strip is o2 1/1 cell + out. Bingo it does go there, try to keep in mind , engine harnesses are complex. bet a real FSM it even shows the actual real path of each wire, this cars wiring is very complex and working on it FSM free, is crazy hard. (doing it for 50 years, and know how)
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Tests/Procedures: 1. Use the scan tool to monitor the O2 sensors. Both should start out as high as 5 volts on a cold engine but gradually come down to the 2.5-3.5 volt range. 2. If either does not, check for a good.
Good luck
that is correct and stated on the first page under P0132. RTM read the manual but , id bet his wires car cut or melted, (its not the PCM , its not the NEW o2 , its the wires are damaged on 99% of cars) not only that you need to buy a scantool and any $10 DMM will work, just as good directly at those 2 pins. this sensor is NOT wide band, and works at 0 to 1v. not 5v, the 5vdc test in the FSM is with the O2 disconnected. (the ECU pulls this line to 5vdc, disconnected ) BOSCH Part # 15510 (read the data sheet if not clear)
are you confusing this FSM statement?
If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will be approximately 5.0 volts. Diagnose the sensor that set the most current DTC.
that is if it shorted, not working right.
the fsm is weak, it has you check for shorts, opens but fails to show how to test for good voltages. sad but true, and is done just like all cars with narrow band sensors. with a volt meter. the scan tool , mine, i can drive and plot 02 readings all day, and log them to my hard drive. it swings fast, and you must understand cross counts. and all that ASE stuff.
yes, op. the ground is tricky if you mess that up,, the all fail. and is tricky because the ECU creats a sensed perfect ground, that if you overload or short, will cause many things to fail. inspect wiring first.
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SOURCE: dtc codes p0155 & p0051
I had the same problem and found out I was sold the wrong sensor, my 4.0 has four, they are all different, when you install a new sensor, you must make sure you clear the trouble code before you start the engine, ignition on engine off, that should do it, it worked for me, also if you have your own scanner and can erase the codes yourself, the wrong 02 sensor will turn engine light on with cold start, then after I erased the code it would stay off all day until the next cold start, thats when I found out my new 02 sensor was for bank 1 sensor 2, and not bank 2 sensor 1, hope this helps
SOURCE: Po136- bank 1 sensor 2
this code is for the 02 sensor heater...there is a relay that sends the voltage to the sensor that may have malfunctioned or there may be no voltage to it
SOURCE: P0155 & P0135
O2 sensors are tricky. sometimes like anything else they fail. many times though the exhaust mixture they encounter is out of their range and that shows up as a failure.since you seem to have no other problems , I would go ahead and change them, but don't be disappointed if the code shows up again (at least you know it's not the sensors.) I don't like using the process of elimination when doing repairs but sometimes you must.
SOURCE: MISFIRE CYLINDER #3 CHECK ENGINE LIGHT COMES ON VEHICLE
Check spark plug wires for corrosion
SOURCE: 2002 Jeep Liberty P0174 code and mech has changed the o2 sensor
Can't tell you exactly what is wrong but the one thing you said is of concern...Map sensor should not be full of oil. If it is, I'd want to know why. In finding the reason for that, you may also find the reason why you are having a problem.
Jeep uses two kinds of engine crank venting. you either have a pcv valve or an orifice controlled system. If either are obstructed it can overpressure the crankcase and cause all kinds of problems.
Years of experience tells me this isn't something I can guess at and be 100% sure I have the right answer but based on what you said, I'd look there first!
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