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Dodge Durango, Dodge, SUV
#671 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [ncdodgeowner]
Mar 11, 2009 (4:57 pm)
Good luck. The moment I have been waiting for. I hope your method includes using the dodge harness bypass. This problem was remedied by dodge but no one including the dealer repair techs have a clue. It is incredible that I couldn't get competent service to get this fixed at my dodge dealer. I tried to tell them what the problem was. I pre-ordered the harness bypass. The corporate auto service division knows about the problem. They made a part to bypass the problem for crying out loud. But somehow the huberous nature of the service department mechanics they "assume" every common problem except what is really wrong with the car. I burned 1300 bucks total on needless repairs including replacing all 8 fuel injectors, 2 O2 sensors etc (no wonder Dodge doesn't bother to do anything about the real problem!). They denied my explanation of the problem and quoted me another 800 bucks to do exhaust repair PCM module replacement and on and on.
When I finally realized I was going to have to tackle fixing it myself, I found it outright scandelous that I can't find out how to install the harness bypass from my dodge dealership, from Dodge corporate, or from any other Dodge source- internet included. In fact this site is the only place this information is being discussed. This is a unique problem to the 2000 4.7L. In 1999 they didn't have a power steering switch (sensor) and by 2001 they fixed the PS design flaw. I agree with Julia there should have been a recall but it doesn't appear one was ever issued. Instead they just threw the replacement part out there and gave no direction to the dealerships to alert the mechanics, parts people, or the public. And we wonder why GM and Chrysler are tanking?
#672 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [mucuna]
Mar 12, 2009 (5:16 am)
I am not using the Dodge Bypass Harness. Given what I have read about it, and the cost, I am simply making a bypass harness myself. I have not seen it, but I assume that the harness offered by Dodge has to be "hard-wired" in to the wire bundle leading to the PCM. I have positively identified the signal wire in the main bundle. It is light green with a red stripe. Unfortunately there is more than one light green wire with a red stripe in the bundle. The other one goes to the transmission. I ended up cutting both to figure this out. There is also an isolated signal ground that is black with a blue stripe. Again, there is more than one of these, so getting the right one is an arduous task. Once I identified both of these, I was able to simulate the signal and watch the Fuel trim response in the PCM with a code reader. I determined that my O2 sensor was bad (another one) so I was unable to complete the hookup just yet.
I purchased a Bosch "Universal-fit" O2 sensor, but am skeptical if it will work, because I have read (and measured) an excitation voltage of 4 volts on the signal circuit. What I have read is that this voltage is part of a 'diagnostic function' that Dodge came up with to test the sensor, and only a Dodge O2 sensor will pass, otherwise setting another code/engine light. I am going to try the Bosch sensor in this setup first, since it is half the price of a Dodge sensor, and see if it works. leave it to Dodge to not only send out a defective vehicle, but make proprietary parts for it as well.
I am going to try this over the weekend and will report back with results. Once I get it all right, I will try to provide more information since Dodge has again "Dodged" the responsibility. By the way Chrysler, I will never buy another of your products, and hope your company folds so we can get junk like this out of America.
#673 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [ncdodgeowner]
Mar 14, 2009 (10:48 pm)
from what I under stand it is only the ground wire that gets contamintated because of a common connection it shares with the power steering ground. It looks like the o2 sensor and PS ground wires join and are connected in the harness about 4- 6 inches above where the upstream sensor wire branch come out. From earlier messages once the PS fluid reaches the o2 sensor connection it can then leak from the ground wire on the harness side into all four wires on the o2 sensor side because of the exposure created at the connection. This can ruin or foul the o2 sensor, the wiring and the connector when you remove and try to test it. I don't know if there is a way to get the PS fluid out of the wires. Other repairs posted involved cutting the connector on the harness side of the o2 connection, replacing all four pins on the harness side of the connector, and bypassing the contaminated ground wire by rerouting an new ground from the o2 sensor to the common ground on the engine block below the water pump.
#674 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [mucuna]
Mar 15, 2009 (4:55 am)
All of the wires get contaminated at the harness connector junction. There are some people running a separate ground wire and getting results, but I would not recommend this approach for two reasons: 1) you leave the O2 sensor wire in the harness with the power and ground wires for the heater, which it can also short to and ruin the sensor/degrade the signal. 2) the O2 sensor ground is not a ground in the sense of most other components. It is an isolated ground from the PCM that all sensors utilize. Grounding sensors directly to the vehicle chassis is grounding them to the same ground as the ignition coils, starter, and other electrically "noisy" components which can result in a bad signal to the PCM, which will create all the same problems as before. This may not occur immediately, or may never occur, but simply "re-grounding" the O2 sensor is not a good idea for a permanent solution.
You can replace the pins in the connector, but this still does not remove the ps fluid still coating all of the wires. While this may remove the immediate cause of the problem, the O2 connector is still the low point on this wiring harness, and eventually will again become the collection point for residual fluid in the harness. I can imagine this is why Dodge created a "bypass harness" since they realized that it was the best thing short of removing the entire wiring harness and cleaning the wires with de-greaser. (a viable option if you are that determined ), or replacing the whole harness - $$. Unfortunately, it appears that most Dodge "techs" are ignorant of how to install it, since it only occured on one model vehicle, in one model year.
I sucessfully finished repairing mine yesterday after 1.5 years of screwing with it, researching it, and letting my Durango sit in the yard (could not get it registered with engine light on)
If you look at an engine wiring diagram (hayes, chilton, etc.) it shows the four wires to the O2 sensor. There is 12V for the heater, a "chassis-ground" for the heater, a signal wire from the sensor, and a "PCM-ground" for the sensor. (I am making up the ground terms to keep them separate, do not look for them in the manual) . I left the sensor connected to the heater and heater ground, since I had proper voltage there, and the heater circuit fuse has not blown. The heater circuit can handle a lot more contamination than the sensor circuit since it can just "burn" through it, so I have left it intact for now since it is not part of the problem.
I ran two new wires from the sensor, the signal and "PCM" ground wires, up to where the PCM is mounted on top of the right fenderwell in the engine compartment. (the black 'signal' and gray 'ground' wire if you are using a Bosch universal replacement) From there I opened the main harness leading into the PCM and located the wires. The signal is a light green with red stripe,(note there are two wires this color, one is O2, one is transmission, I used trial and error) and the "PCM isolated ground" is black with a blue stripe. The signal wire must be cut, and the new wire from the sensor connected to the end going into the PCM. If you do not cut it, but rather spice it, you have essentially left your sensor connected to the point of contamination that you are trying to avoid. The ground wire must be spliced into the one in the harness bundle so as not to disconnect other devices using the same ground. I used an automotive crimp style spice sold at auto stores.
So far I have driven 70 miles with no problems. I have a scanner, and both oxygen sensors are reading fine. The front sensor switches from 0.080 volts to 0.810 volts at a regular interval. The system is running in closed loop mode like it should, and there is no engine light.
I understand this may be somewhat vague if you are not somewhat handy with automotive wiring, but this post is half a novel already so I will leave it at this for now to see what areas are clear and which are not so they can be answered in future posts. If I get the time I would like to put the whole procedure on a webpage with pictures since Dodge is not really helping anyone and this is the only place on the entire web that is.
#675 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [ncdodgeowner]
Mar 15, 2009 (10:15 am)
very informative. There is room for a website where expert mechanics post detailed repairs and answer questions. It would be awesome to see this website take that on,
I'm sure whoever does it that it could be monetized with ads from every auto part store.
I still have a couple questions.
Do you know the wire colors from the original factory o2 sensor- Are they the same as the Bosch?
You determined the correct wire between the two same-colored wires in the harness the PCM (tranny vs O2) using "trial and error". What procedure did you perform, and what result were you looking for, to determine which was the correct wire?.
Let us all know the name of the webpage if you create it.
#676 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [mucuna]
by Stever@Edmunds HOST
Mar 15, 2009 (10:24 am)
I think you're there.
There's also Edmunds Answers.
Mostly the trick is using the search tools if you have something specific you need info on and then post if you don't see a thread that helps.
#678 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [ncdodgeowner]
Mar 19, 2009 (1:24 pm)
I do have a (possibly stupid) question, if the PS fluid has made its way to the connection on the PCM, will the bypass wiring solution (running seperate ground from O2 sensor 1 to PCM) still work? thanks!
#679 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [steve_]
Mar 19, 2009 (2:04 pm)
FINALLY!!!! ladies and gentlemen, I want to express on how HAPPY I am to find this thread. To date, my Fiance and I (her 00 Durango 4.7L) have spent in excess of $700 thus far trying to figure out this friggin problem. The local shop we had it at recognized the issue, but simply unplugged the harness from PCM and cleaned it. 3 consecutive days in a row, trying to get all the PS fluid out. Still yet, she drives a mile or so and I don't need to explain how the thing runs. Crappy mileage, heavy soot, and it hardly wants to accelerate and sometimes lurches while at stops. I am going to try unplugging the upstream O2 sensor as described previously, just so she can drive it for the time being until we can get enough $$ saved to try and do this bypass harness. Darned Durango has costed us some of our wedding fund!! LOL just trying to keep it light, thanks to all who are posting here to help out!!!!!!!
#680 of 853 Re: o2 sensor + power steering pressure switch Dodge Durango Nightmare [durangoroo]
Mar 19, 2009 (8:18 pm)
the fluid leaks through the wires from the PS unit to a junction that branches into larger harness about 6-8 inches above the right upstream o2 sensor. Fluid can be seen leaking at that junction and at the O2 sensor outbranch and connection These are the low points in the harness. The PCM on the other hand is way upstream on the terminal end of that section of the harness. To high up to get contaminated (i hope). I suppose if the PS fluid was really leaking bad and had some pressure behind it PS fluid could travel or "wick" uphill and contaminate the PCM but it seems unlikely.. ncdodgeowner's method would likely provide a clean connection by grounding at the or near the PCM using a splice. The other 3 wires can get cross contaminated at the o2 connector from the old ground wire leaking PS fluid at the connector pins and then recontaminate the new ground. A very early message talked about replacing all 4 pins on the harness side of the connector and using a new o2 sensor because those wires are contaminated for sure. Still waiting to hear from ncdodgeowner's repair to see how it worked out and anymore specific details of the repair