[Capnmor02]

I already replaced bank 1 sensor 1 two times and code still won’t clear. I noticed with my scanner that there is no voltage showing. Bank 2 is showing voltage. How can I clear this cel? Is it a bad fuse-relay? Wiring all looks good.

 

[sdspeed]

if your scanner isn't clearing it you might try pulling the EFI relay for a few minutes.

 

[Capnmor02]

Is that just like disconnecting the battery?

 

[sdspeed]

Less disruptive, allows the capacitors in the ecm to discharge.
Either or !

 

[Capnmor02]

Less disruptive, allows the capacitors in the ecm to discharge.
Either or !

Ok thank you I’ll try it

 

[foxtherouge]

If you've replaced the sensor and it's reading at no power you might want to check to see if the sensor is actually getting power or not. You might have another issue.

 

[Capnmor02]

If you've replaced the sensor and it's reading at no power you might want to check to see if the sensor is actually getting power or not. You might have another issue.

How can I check to see if it is?

 

[foxtherouge]

Repair Guides

AutoZone Repair Guide for your Engine Performance & Emission Controls Components & Systems Heated Oxygen Sensor

www.autozone.com

I know that it says it's for a 2001 Camry but then later says 1zz/2zz but the wiring is the same.

 

[Capnmor02]

Repair Guides

AutoZone Repair Guide for your Engine Performance & Emission Controls Components & Systems Heated Oxygen Sensor

www.autozone.com

I know that it says it's for a 2001 Camry but then later says 1zz/2zz but the wiring is the same.

Thank you

 

[John Anthony]

Does your scanner have the ability to clear a code and you did that and the code came back? Or do you mean you haven't cleared the code and it won't go away after your fix? Just because you have that code, it doesn't necessarily mean that you should have replaced the A/F sensor, although that is often the fix. Did you use Denso sensor #234-9021 ?

If your new A/F sensor is presumably good and the correct part #, it has to be the wiring to the sensor regardless of how it looks. It can look perfectly fine, but have a short or open in it. As a very rare cause, it could be a faulty ECM. There is a certain protocol to diagnose the wiring and that is how you will know for sure. I did that on my Gen 9 Corolla for a similar O2 sensor code and the wiring looked fine, but I had to figure out which wire in particular was faulty and I had to bypass it with a new wire (a shielded wire in this case was faulty) that I had to run all the way up to the ECM. Left the bad wire in place in the harness where it will do no harm.

 

[Capnmor02]

Does your scanner have the ability to clear a code and you did that and the code came back? Or do you mean you haven't cleared the code and it won't go away after your fix? Just because you have that code, it doesn't necessarily mean that you should have replaced the A/F sensor, although that is often the fix. Did you use Denso sensor #234-9021 ?

If your new A/F sensor is presumably good and the correct part #, it has to be the wiring to the sensor regardless of how it looks. It can look perfectly fine, but have a short or open in it. As a very rare cause, it could be a faulty ECM. There is a certain protocol to diagnose the wiring and that is how you will know for sure. I did that on my Gen 9 Corolla for a similar O2 sensor code and the wiring looked fine, but I had to figure out which wire in particular was faulty and I had to bypass it with a new wire (a shielded wire in this case was faulty) that I had to run all the way up to the ECM. Left the bad wire in place in the harness where it will do no harm.

Yes to Denso 234-9021 and yes I cleared the code with my scanner. It comes back on within 30-60 seconds

 

[John Anthony]

Here's what I found:

We assume your new Denso sensor is good, so according to this info it has to be the wiring (or the ECM). My guess is one of the wires from the AF sensor has a short or open in it somewhere between it's connector to EFI main relay or there's an open/short between the EFI main relay and the ECM.

The first thing to do is rule out a problem with the ECM. You do this first because it's easy to test. Remove the glove box. Find the ECM. There should be four connectors to it. Each connector has a cable with a bunch of wires coming out of it. You want to use your voltmeter to check for voltage between port HTAF of the rightmost connector and body ground when the ignition switch is in the on position. You should measure between 9 and 14 volts. If you don't have 9-14 volts, then something is wrong with the ECM. "Rightmost" is assuming the tabs for each of the four connectors are at the top. If the ECM is installed upside down (tabs at the bottom) then it would be the leftmost connector. Assuming rightmost connector, HTAF is the second from the right port of the top row of ports. I will send you a private message conversation showing you which connector port is HTAF.

 

[Capnmor02]

Thank you so much. I was thinking ecu also. I’ll try these steps and hopefully find the issue.