Re: I got codes - 98 Sienna


"Tomes" <askme@xxxxxxxx> wrote in message news:wtL2i.7294$296.5296@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
"Ray O" ...
"Tomes" ...
OK folks, my check engine light came on and I would like to know what to do. 1998 Sienna, 190K miles. Overall reliable vehicle. This may be 2 separate issues that coincidentally occurred, or they may be related. Please help me sort this out, thanks. I plan to take this on a camping trip for a 2.5 hour drive Friday. Without it I cannot pull the trailer....

A short bit of history first. Son went to work and called saying that the car is dead there. There has been no indication of anything going wrong before that; this was a sudden event. It had no response to turning the key after sitting for maybe 2-3 hours. I arrived in the Jeep and jump started it. It was really dead - I had to let it sit there and suck juice from the Jeep for a while for it to turn fast enough (meaning do more than just clicking). Then it started up and seemed fine. I don't know why it went dead. I put it on a charger and it took a full charge according to the charger.

When Son drove it home from the park he says that the check engine light was now on at that point. Sienna seemed to drive OK coming home and for a next 12 mile round trip. Now I pulled the codes today and there are 2 of them as follows:
First Code:
PO155 Mod$10
O2 sensor Heater Circuit Malfunction
Bank 2 sensor 1
Second code:
PO155pd Mod$10
O2 sensor Heater Circuit Malfunction
Bank 2 sensor 1 (same as first code but with that additional pd)

Then I pulled the "Freeze Data" (if this helps)
Engine RPM 1508
Calc Load % 14.1
Coolant deg F 185
IATdeg F 95
LT FTRM1(%) 0.0
ST FTRM1(%) 5.5
LT FTRM2(%) 5.5
ST FTRM2(%) 3.1
Veh speed (mph) 45
Fuel sys 1: CLSD
Fuel sys 2: CLSD

OK so here are my questions (If I should be posing other questions let me know)
1) What exactly do I need to do about this?
2) Is it easy enough for me (I am reasonably adept, but not a superstar)?
3) Can I go on the trip without doing it and what would be the consequences?

I have one afternoon to do it - tomorrow.
Thanks for this help folks.
Tomes

1) If the battery is older than 5 years old, consider getting it replaced. Check the battery terminals to make sure the clamps are good and tight and free from corrosion. Check the electrolyte level in the battery. Are there any aftermarket items installed like remote starter, satellite radio, etc? I would deal with the battery before the trip.

2) The check engine light is probably not related to the dead battery, and a bad O2 sensor heater circuit will not leave you stranded if you do not deal with it before you go. Where are you going camping? I'll be up near Wild Rose, WI working on a climbing tower.

I am pretty sure that the "pd" on the second code has something to do with a pending code. Go to this web site: http://oregonstate.edu/~tongt/camry/index.html and under generation 4 Camry V6, look up the diagnostics section. It will take a long time to load, scroll down to the V6 engine and look up DTC P0155 to see how to check the O2 sensor with an ohm meter.

Have a great weekend camping!


Thanks Ray, much appreciated. I gotta get a pair of new front tires tomorrow so I will get the battery at the same time. I don't know how old it is, but it is likely old enough. Do they just up and go like that? It was not slowing up to that point. I did clean the terminals; the battery is 'sealed'; I do have aftermarket trailer power going to the battery, but that has not been an issue up to now. I was expecting to see some manner of alternator code, but it is not to be, so I guess that is OK.

So for 2), will I eventually need to replace something, like the O2 sensor? I am relieved that I ought to be OK for this weekend, that helps a lot. I just gotta keep the wife from seeing the light <grin>.

We are going to the Spring Gulch Folk Music Festival in eastern PA. We do that every year and it is a blast. We listen to the professionals play during the day until midnight and then play all night among ourselves. Performers: Patty Larkin, Richie Havens, Michael Braunfeld, Trout Fishing in America, Greg Greenway, Jan Krist and Jim Bizer, Girlyman, John Flynn, Juggernaut String Band, Kruno Spisic & The Gypsy Jazz Giants, Gandalf Murphy and the Slambovian Circus of Dreams, Nora Jean Bruso Blues Band, Slaid Cleaves, Laurie Lewis and Tom Rozum, The Holmes Brothers. Most of these I have never heard of, but that is one reason to go. I end up greatly expanding my musical horizons at these things, both in listening and in playing with folks. My personal faves on this list are Trout Fishing in America, Girlyman and Gandalf & the Slambovians. Great stuff. For me it is mostly a washtub bass weekend with perhaps a little bit of hammered dulcimer, but not much of that.

Thanks again,
Tomes


The O2 Sensor has a heating element inside to bring it to operating temp sooner than it will get there without the heater.

If the sensor is cold, then the mixture is going to be rich resulting in slightly higher fuel consumption. Consider that in the olden days, the carburator controlled rich and lean, then as time went by the engineers figured out ways to electronically control the carburator to manipulate rich and lean differently than a purely mechanical carb does the same job.

When O2 Sensors came along, the early ones are akin to the old mechanical carburators, they needed to be heated by engine operation in order to adjust mixture settings. The engineers found that if they heated the O2 Sensor independently of the engine operation, they could get the mixture to lean out (turn the choke off*) earlier and thereby reduce emissions.

Your O2 Sensor has a heater inside that is not working. The result will be that the fuel mixture remains on the rich side (choke activated) longer than is actually necessary. Once the engine reaches full operating temp, the O2 Sensor will be working normally, and the internal heater is not needed -- or used -- anyhow.

( * ) Your car has no choke, per se. I only tossed that out to give you an idea of what the heater in the O2 Sensor is trying to accomplish.


.

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