2005 dodge caravan

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#1
Please fill out the following to ask a question.

MAKE: dodge
MODEL: caravan
YEAR: 2005
MILES:
ENGINE: 3.8
DESCRIBE ISSUE....I have a 2005 dodge caravan, the check engine light is on I ran the code and it said high voltage on upstream o2 sensor .. I replaced the o2 sensor cleared the code check engine light stayed off till I shut the van off then restarted it .. Light came back on I rescaned it .. Same code I said heck with it kept driving the van for a while had a few 90 degree days and the van started "hunting " rpm up and down on idle wanting to die .. That quit once the weather cooled down I finally decided to buy another o2 sensor still samething ..... Ok after the long story here's my question ... This van has all the bells and whistles... DVD ,heated seat and so on... I've noticed the a alternator is sqeaking and has been this whole time but no signs of the battery not charging good or anything... And I figured that the code wouldn't be saying high voltage if the alternator was bad , wouldn't it be low voltage ... Anyway I've got a van with a check engine light and the code says o2 sensor ... Lol any ideas could my alternator be playing a part in this whole mess....
 

kev2

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#2
first thing - there is NO code that says a sensor is bad - they alert to a problem with that system
Post ALL the codes you are getting - use a scanner the key trick will not show all codes.
The explanation of codes varies somewhat and part stores always state then as a part is bad SO let us know # and we will advise.

Be careful with purchasing sensors aftermarket parts are 'lacking' in quality. Was this a wire yourself type sensor?
 
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#3
"High voltage" code for a O2 sensor usually means that power from the O2 heater circuit (12-14v) is leaking into the signal circuit (0-1v). Replacing the sensor usually fixes this problem. If it reoccurs, it might be a wire harness issue, a ground circuit issue, or a computer issue. Having a scanner to see what the actual signal voltage is would be helpful.
 

nickb2

Wrench. Diagnostic Tech.
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#4
I am going to assume this is either a p0132 or a p0138.

Plz confirm as asked before. Proper way to study this is to see what the PCM is seeing. Anything above 3.7v is suspect, it will code if it stays at 3,9v for 30 seconds or more.

If you follow normal troubleshooting, you don't replace a sensor until all the pin tests are done. The harness needs to be pin tested for a short to voltage on two circuits. One is the signal circuit, the other the return circuit. This will rule out any short to voltage which may cause a high voltage code for the O2 sensor.

Once that is ruled out, you then ohm test the circuit to and from the PCM to the O2 sensor in question. This will rule out any problems in the circuit such as a restrictive wire, a cut/open wire or a short to ground etc.

Once that is tested as being good, then you move on. You ohm check the actual o2 sensor by placing a jumper between the signal and return circuit and monitor voltage, if voltage is between 2.3 - 2.7v, you may then safely replace the actual sensor. If that checks out ok. You then check PCM connectors for any corrosion. If that checks out ok, then and only then do you suspect a bad PCM.

This is why we say throwing parts at a car is often of no avail. That is backwards testing. If I was a doctor, and I said I am not sure if it your hip joint or your hip ligament that is hurting you, but I will try a new titanium hip in there and we will see.if that part swap works. Would you go through that operation on a whim of uncertainty? I would certainly hope not. I am pretty sure you would either ask the doctor to do more through testing or seek a more informed opinion.

When you see a supposed technician swapping parts to try to find a problem, that usually means he or she does not know or does not wish to troubleshoot a problem and is either lazy or incompetent. In either case, it always ends up with hard earned cash being thrown in the waste bin. When we ourselves do this sort of shoddy work, we usually BS ourselves and say "hey, at least it has a bunch new parts, those ones were getting old."

The art of a bullshitter, bullshitting another bullshitter. :eek:;):beer:
 
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