Check engine light 2004 toyota sienna


#1

We just bought a 2004 Toyota Sienna XLE Van (5 days ago), and need to drive down from South Bend to Nashville, TN (450 miles). But this Saturday the check engine, vehicle stability control and traction control lights turned on. From what I can tell from researching the web, the VSC and TC lights turn on as a result of the check engine light turning on. Took the van to a parts store and got the following codes:

P0031, O2 sensor heater control circuit low - bank 1 sensor 1,

P2238, O2 sensor or A/F ratio sensor circuit low- Bank 1 sensor 1.

Probable Causes:

1. Open or short circuit condition (no visible evidence)

2. Poor electrical connection (not sure where to get a wiring diagram)

3-P0031. Failed O2 sensor

3-P2238. Failed AF sensor

4-P0031. EFI Relay Fault

4-P2238. Fuel pressure, vacuum leak, MAF sensor fault.



Attempted repairs:

1. Checked the fuel cap (saw this has set the CE light off)

2. Replaced Air Flow sensor, by air filter (which I verified to be quite new)



All three lights went back on, even though above repairs were done and the computer had been reset.



At this point, I’m due in to work on Monday at Tennessee. The movers will be moving furniture in to our home on Monday.

We need to drive down this Sunday.



The van appears to drive just fine, except for the “lights of doom”.



Can we safely drive the van to TN,

and have it serviced down there?



Could we cause any further damage to the van if we drove it down to TN?


#2

When the check engine light comes on, it is meant to get your attention. It’s an early warning system. It does NOT mean total meltdown is imminent. I suggest you can safely drive the van to Nashville and have it serviced there. Many people drive for weeks with the CEL on, and I’m assuming your trip will take only one day. Check all the fluid levels before you leave. Assuming they are all OK, 450 miles is not going to hurt anything.

If the VSC and TC lights are on, these systems are most likely disabled, so keep that in mind. No stability control and no traction control, which is how many of us drove for years, and still do.


#3

Why did you mess with the MAF sensor when both codes point first to the O2 sensor? The O2 sensor is what seems to be bad. And, this van uses that O2 sensor as part of the fuel management algorithm. It could cause problems on the road if ignored.

Any independent mechanic can change this out for you. You may want to get it fixed right before you go.


#4

I have an 04 Sienna and had the exact same problem. Dealer replaced the O2 sensor and it fixed the problem.