Getting error codes 0031 & 0037 on my 2001 Regency Conversion with 5.2L engine. Codes state:
0031 Heater Circuit Low Voltage Bank 1 Sensor 1
0037 Heater Circuit Low Voltage Bank 1 Sensor 2
I've replaced the pre-cat O² sensor and cleared the codes. The engine malfunction light does not come back on at idle, but illuminates as soon as the vehicle is driven for approximately ½ mile.
When left idling for longer periods of time (i.e. 10 minutes of slow traffic), the engine will experience a severe lack of power until 'nursed' back to running normally.
This is my second Dodge Conversion (first was a '98 PMC) and I love this vehicle...but my patience is being severely tested.
Help? :help:
stev
08-07-2007, 11:07 AM
P0031 = 02 Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
What does that mean ... Shorted low condition detected in the oxygen sensor 1/1 heater elementcontrol feedback sense circuit
P0032 = 02 Sensor Heater Control Circuit High (Bank 1 Sensor 1)
What deos that mean ... Shorted high condition detected in the oxygen sensor 1/1 heater element control feedback sense circuit
It sounds as if the O2 sensors are either not pluged in right, that the sensors are either wide or narrow band, wrong sensors for the van, or have shorted to a ground.
Since P0030 code was not thrown, I would suspect that the O2 sensors are not wired correctly or are the wrong type of O2 sensor.
Here's some help with Dodge Ram O2 sensors. http://dodgeram.org/tech/gas/Trouble/O2_sensor.htm
Other than the help from the PDF above, you may need to clean or replace the IAT sensor too. This helps the PCM/ECM to set the injection timing and adjust the air-fuel ratio that works with the O2 sensors. In some rare cases, the IAT was actually at fault rather than the O2 sensors.
Even new O2 sensors can have issues. Some are a generic of one-size-fits-all. BUT, those may not work well in our vans. Some O2 sensors are narrow-band while others are wide-band. See this link for further info ...
http://dodgeram.org/tech/gas/Trouble/O2_sensor.htm
The MIL gives an indication to the vehicle operator when the Powertrain Control Module (PCM) has recorded a Diagnostic Trouble Code (DTC) for an On-Board Diagnostics II (OBDII) emissions-related circuit or component malfunction. The MIL is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the PCM over the Programmable Communications Interface (PCI) data bus.
The MIL bulb is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the bulb will always be off when the ignition switch is in any position except On or Start. The bulb only illuminates when it is provided a path to ground by the instrument cluster transistor.
The instrument cluster will turn on the MIL for the following reasons:
BULB TEST - Each time the ignition switch is turned to the On position the MIL is illuminated for about three seconds as a bulb test.
MIL LAMP-ON MESSAGE - Each time the cluster receives a MIL lamp-on message from the PCM, the indicator will be illuminated. The indicator can be flashed on and off, or illuminated solid, as dictated by the PCM message. For some DTC’s, if a problem does not recur, the PCM will send a lamp-off message automatically. Other DTC’s may require that a fault be repaired and the PCM be reset before a lamp-off message will be sent.
COMMUNICATIONS ERROR - If the cluster receives no lamp-on or lamp-off messages from the PCM for twenty consecutive seconds, the MIL is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid lamp-on or lamp-off message is received from the PCM.
MIL illumination
In many instances, emissions systems must fail diagnostic tests more than once before the PCM illuminates the MIL. These tests are know as 'two trip monitors.' Other tests that turn the MIL lamp on after a single failure are known as 'one trip monitors.' A trip is defined as 'start the vehicle and operate it to meet the criteria necessary to run the given monitor.'
Certain conditions such as a loose or missing gas cap, poor fuel quality, etc. may illuminate the light after engine start. The vehicle should be serviced if the light stays on through several typical driving cycles. In most situations, the vehicle will drive normally and will not require towing.
Prolonged driving with the "Malfunction Indicator Light" or "Check Engine" light on could cause further damage to the emission control system. It could also affect fuel economy and driveability. The vehicle must be repaired before any emissions test can be performed.
If the light is flashing, severe catalytic converter damage and power loss will soon occur. Immediate service is required.
Retrieving codes:
Turn the ignition key until the digital odometer displays, repeat three times in succession and then back to "On" (On/Off, On/Off, On/Off, On). At the fourth "On" the odometer will be replaced with codes. If no codes are present then "Done" will appear.
Erasing codes:
After three good trips the MIL is extinguished and the Task Manager automatically switches the trip counter to a warm-up cycle counter. DTCs are automatically erased following 40 warm-up cycles if the component does not fail again.
DTCs can be erased anytime with a DRB III. Erasing the DTC with the DRB III erases all OBD II information. The DRB III automatically displays a warning that erasing the DTC will also erase all OBD II monitor data. This includes all counter information for warm-up cycles, trips and Freeze Frame.
IceAce
08-07-2007, 03:08 PM
It sounds as if the O2 sensors are either not plugged in right, that the sensors are either wide or narrow band, wrong sensors for the van, or have shorted to a ground.
Since P0030 code was not thrown, I would suspect that the O2 sensors are not wired correctly or are the wrong type of O2 sensor.
Here's some help with Dodge Ram O2 sensors.
This PDF may be of some help to you.
Other than the help from the PDF above, you may need to clean or replace the IAT sensor too. This helps the PCM/ECM to set the injection timing and adjust the air-fuel ratio that works with the O2 sensors. In some rare cases, the IAT was actually at fault rather than the O2 sensors.
Wow...that's exactly the type of information I've been searching for!
I've had this mechanically sound van for 16 months (it's our second one) and this is the first time I've encountered this type of code. I'm very comfortable doing my own oil, brakes, tune-ups, etc...but this has been an entirely new animal.
The PDF makes for some interesting reading and gives a troubleshooting flowchart which I will follow tonight.
I appreciate the time it took to provide all of this information and will report my findings in a follow-up post.
Hmmm...I had a tough time submitting this until I removed the URLs from the quoted section. I'm assuming that I do not have URL posting permission as a new user...any idea when this privilege is granted?
IceAce
08-08-2007, 01:31 PM
Alright...I get home last night all fired up and ready to find the source of this MIL and I can't find the A/F Sensor. To add insult to injury, the A/F Heater Relay does not appear to be located in the usual bank of relays next to the battery in the engine compartment.
Where do I look for the Sensor & Relay? :help:
IceAce
08-10-2007, 02:03 PM
Where do I look for the Sensor & Relay? :help:
::: Crickets chirping :::
Anybody? :dunno:
van-nut
08-10-2007, 10:07 PM
Not sure what you're reffering to on either the A/F sensor or the A/F relay?? I have never herd of either of those. :dunno:
What does A/F stand for?
Pete
koihito
08-10-2007, 10:37 PM
I don't know it Regency is the same, but Mark III relocated some of the heat/air relays and fuses to a box on the wall just behind the drivers seat.
IceAce
08-11-2007, 01:31 PM
What does A/F stand for?
Pete
A/F is Air-Fuel...and according to the .PDF posted by Stev, the scan code P0031 relates to the Air-Fuel Ratio (A/F) Sensor.
"When code P0031 is set, the ECM enters fail-safe mode. The ECM turns off the A/F sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned to off."
The troubleshooting flowchart is as follows:
1. Inspect Air Fuel Ratio Sensor (Heater Resistance)
a. Disconnect the A4 Air-Fuel (A/F) sensor connector. This is the sensor I cannot find! :huh:
b. Measure the resistance between the terminals of the A/F sensor connector. [Reference chart indicated]
c. Reconnect the A/F sensor connector.
2. Inspect Air Fuel Ratio Sensor Heater Relay (A/F Heater Relay)
a. Remove the A/F HEATER relay from the engine room R/B. ...and this is the relay I cannot find! (What's R/B?) :huh:
b. Check the A/F HEATER relay resistance. [Reference chart indicated]
c. Reinstall the A/F HEATER relay
I'm going after this again today...maybe the clear light of day and lack of a time window will allow me to more thoroughly inspect the electrical system.
Any advice would be appreciated! ;)
van-nut
08-12-2007, 01:31 PM
IceAce - I really wish that PDF had some info somewhere that told which models and years it is applicable to. I could be wrong, but it sure seems to me that that info is for the previous generation throttle body FI systems - late 80's - early 90's.
The FSM for my 98 makes no mention of any A/F sensor or A/F heater relay. In fact, looking thru the schematics, it looks like the only relay which is part of the oxygen sensor circuit is the ASD (auto shut down) relay.
Pete
IceAce
08-12-2007, 01:46 PM
Hi Pete,
Thanks for the reply. I spent about four hours yesterday chasing ghosts and came to a similar conclusion.
This thing really has me baffled and I'd really like to get it fixed before the cat goes out also...
Option #1. ~ I've got a guy who specializes in electrical work...but he's $$$. :bawl:
Option #2. ~ I've also got a dealership who wants a crack at it...but I don't know them well enough to trust them. :banghead:
van-nut
08-12-2007, 02:11 PM
I can't say I blame you for not trusting the dealer. Some are great, others totally suck. A real "box of chocalates"
So just to make sure I am understanding correctly, you initially got both codes at the same time, and replaced only the pre cat O2 sensor?
The heater portion of the circuit is pretty simple. I believe that nothing changed from '98 to '01, so your van should be the same as mine. The schematic shows that each O2 sensor gets its own voltage supply for the heater straight from the PCM (Powertrain Control Module, aka "the computer"). Then each is grounded back to the PCM thru one common ground wire.
The ASD relay which I mentioned earlier is not part of the heater circuit, but it is part of the sensor circuit. The sensor portion and the heater portion are two completely separate circuits.
Pete
IceAce
08-12-2007, 02:45 PM
Pete...thanks again for the reply!
I can't say I blame you for not trusting the dealer. Some are great, others totally suck. A real "box of chocalates"
I agree...and asking a dealer to chase down an electrical problem is akin to writing a blank check.
So just to make sure I am understanding correctly, you initially got both codes at the same time, and replaced only the pre cat O2 sensor?
Yes...since the van has 74,000 miles I wanted to eliminate that as a symptom first.
The schematic shows that each O2 sensor gets its own voltage supply for the heater straight from the PCM (Powertrain Control Module, aka "the computer"). Then each is grounded back to the PCM thru one common ground wire.
Do does your wiring schematic show what color the voltage supply wire is? The reason I ask is that I did find a purple w/pink stripe wire which had grounded out through a worn out spot in the harness.
Knowing what color wire to trace would certainly be helpful information to have.
The ASD relay which I mentioned earlier is not part of the heater circuit, but it is part of the sensor circuit. The sensor portion and the heater portion are two completely separate circuits.
Thanks...I discovered yesterday that pulling the ASD relay instantly kills the engine!
I just noticed that you're from Arvada. That has been one of our more frequent hockey destinations every spring with JrAce. It's a beautiful place with a lot of wonderful people!
IceAce
08-12-2007, 06:10 PM
SUCCESS!!!
Call off the hounds!
The O² sensor heater wire was grounding on the AC compressor. The wire has been spliced, codes erased, and a 20 mile test drive points to all systems go.
I'll post pics when reassembly has been completed.
Thanks to ALL who responded and helped out with this not-so-fun experience.
van-nut
08-12-2007, 06:37 PM
Great news!!!
I was just about to post and tell you that I mis-read the schematic and had the sensor and heater circuits backwards. The ASD IS actually part of the heater circuit, and the PCM controls the sensor part of it. DUH, I should have known that! :crazy:
Anyway, glad you got it figured out.
Don't be a stranger. Always new stuff to learn here on the forum. :cool:
Pete
IceAce
08-12-2007, 07:43 PM
Don't be a stranger. Always new stuff to learn here on the forum. :cool:
Pete
I've learned a ton while searching the forums already!
Here's the harness that melted and grounded to the AC compressor:
I spliced the wire, recovered the harnesses with flame-retardant conduit, and zip-tied them in an out of the way location. The fix didn't work immediately as this fuse (the O² sensor fuse) had blown:
Again...many thanks for all of your collective help...I promise to not be a stranger around these parts!
Ed
stev
08-16-2007, 12:22 PM
Ed,
That is really some exciting news! It's great that you had gotten back to the group here in the forums, and even more so posted a good set of images to boot! :)
Some of the threads in the forums have questions asked, but the originator of the posting never returns. So we never know what the outcome was whether good or bad. :dunno:
This is one successful thread that others will glean great information from in the future! Good work on your part and the others in this forum. :cheerl:
Now that the van is running great, keep us posted on the things you do with it. There are a few top sticky's in this forum for the Ram Van that are topic for those postings. So, enjoy! :D
PS, when you did the cap-n-rotor, did both have cooper/brass contacts? If not, you could run into troubles down the road shortly. The aluminum contacts will fail leading to engine stalls and hard starting. In some cases, the ignition coil goes bad too. Hope this info helps you too.
IceAce
08-16-2007, 04:23 PM
Ed,
That is really some exciting news! It's great that you had gotten back to the group here in the forums, and even more so posted a good set of images to boot! :)
Some of the threads in the forums have questions asked, but the originator of the posting never returns. So we never know what the outcome was whether good or bad. :dunno:
Since I do a lot of troubleshooting on a non-vehicle related board (HInt = :drink: ), I've experienced the frustration involved in providing tons of technical information only to receive zero feedback. :VHOT:
This is one successful thread that others will glean great information from in the future! Good work on your part and the others in this forum. :cheerl:
It is my sincere hope that this thread may assist anybody else who experiences this oddball problem.
Now that the van is running great, keep us posted on the things you do with it. There are a few top sticky's in this forum for the Ram Van that are topic for those postings. So, enjoy! :D
As you probably already read, I cleaned my (very, very dirty) IAC and performed the breather mod which, IMO, needs a 'sticky' too.
PS, when you did the cap-n-rotor, did both have copper/brass contacts? If not, you could run into troubles down the road shortly. The aluminum contacts will fail leading to engine stalls and hard starting. In some cases, the ignition coil goes bad too. Hope this info helps you too.
Thanks for the head-up on that...the new cap-n-rotor are aluminum, so I'll replace those with the copper/brass type next time the doghouse has been removed! http://andrewager.com/blather/images/smiles/yep.gif Where would I find this particular cap-n-rotor set?
stev
08-16-2007, 07:18 PM
Ed,
A copper/brass contact cap-n-rotor set can be easily purchased from AutoZone, Pepeboys, NAPA, AvancedAuto and the like.
At the AutoZone, the cap was only a mere $4 more over the cost of one with aluminum contacts. The brand was WELLS. The $4 dollars is money well spent to provide better firing and no fouling of the contacts. This saves more money in fuel costs.
YES, at one time the crankcase breather mod was a sticky, but somehow it had gotten unstuck. I would highly recommend anyone to do this mod to ensure that oil residue would not build up on the air filter. Having an oily air filter blocks air that starves the engine. A starved engine will burn more gas as the pedal is push further to the floor to make up the power loss.
One level above this Van forum is a [u]"Van and Cargo Truck Articles"[u]. It would in the forums BEST interest to make a stick under each of the various van types that would point to the new articles. Many people do not know about bumping up one level to find the link.
The How-to: Clean the IAC, is already there. The next one needed is the Crankcase breather mod. :)
landyacht318
08-19-2007, 02:20 AM
Hey Stev, I just did a search for your crankcase breather modification and read the whole thread. I gotta say it is a real nice modification. I always wrongly assumed that the engine vaccuum at the TB would only pull air from the crankcase, thus ignoring the term 'breather'. I thought it was just a weaker version of a pcv valve.
I have cleaned my stock ccb a couple times and never found it to be clogged, nor to be particularly dirty. I also dont see how it could be a particularly effective filter, as the media inside is quite porous. But I have also never found any oil on my air filter. In one of your posts you said there was no foam like filter in your stock 'bell' and that the replacement cost almost 25 bucks or so. I found an air tex, fram and an ac delco all for under 5 dollars on www.rockauto.com. Maybee different year/ styles.
As I frequently drive on extremely dusty conditions I'll probably perform your modification as extra insurance. He**, when I'm on those dusty roads in Baja I run an additional air filter on the end of the snorkel.
Good mod, keep em coming
IceAce
08-19-2007, 03:53 AM
...I also dont see how it could be a particularly effective filter, as the media inside is quite porous. But I have also never found any oil on my air filter. In one of your posts you said there was no foam like filter in your stock 'bell' and that the replacement cost almost 25 bucks or so. I found an air tex, fram and an ac delco all for under 5 dollars on www.rockauto.com.
Good mod, keep em coming
The breather material need not be ultra-thick...it just needs enough material to keep oil from hitting the air filter while also preventing insect parts from being drawn into the valve cover. The air filters on both my 318's have always seen a solid dosage of oil...a situation I am all-too-happy to prevent.
My stock breather 'bell' was free-flowing with no filter media of any type...unlike my $6 chrome replacement which has a small foam insert.
landyacht318
08-19-2007, 12:30 PM
I was referring to the stock crankcase breather filter not being very effective, not stev's modification.
I've got a K&N and maybee I just never noticed any motor oil, but I'm gonna go lift the doghouse and have a look. I don't know if my current breather is the original, but I've never changed it in 6 years, just cleaned it.
IceAce
08-19-2007, 01:03 PM
I was referring to the stock crankcase breather filter not being very effective, not stev's modification.
LOL...we're talking about the same item in different situations. My van does not have a stock breather element...thus all of the oil on the air filter and the need to add a breather.
landyacht318
08-19-2007, 05:44 PM
I did just find some bug parts sitting on top of my breather bell and some crap in the hose, but no oil other than the pink K&N stuff on the air filter. Maybee I can get away with a piece steel screen glued or riveted over the hole. Maybee since I have so much other crap to do on the interior I'll do nothing. LOL :crazy:
stev
08-20-2007, 01:59 PM
I agree that the stock crankcase breather bell doesn't help a whole bunch. The bell alone is somewhat pricey depending on where you purchase it.
Yes, the breather foam/fabric in the mod is by far the best route to go AND the replacement cost for the breather element is a few dollars vs. the pain of the breather bell mess.
