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RIP
RIP, Lead Technician
Category: Honda
Satisfied Customers: 5591
Experience:  Master ASE technician, Honda/Acura aftermarket training, Hybrid training, Adv. level L1
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Code P0135 on my 97 honda civic, I also checked

Customer Question

Code P0135 on my 97 honda civic, I also checked the voltage coming from the engine side of the harness, but did read any on any of the pins.
Submitted: 9 years ago.
Category: Honda
Expert:  RIP replied 9 years ago.

Michael,

Did you already replace the upstream oxygen sensor, or did you measure the resistance accross the oxygen sensor heater? Thanks,

-Rip

Customer: replied 9 years ago.
I haven't changed anything yet, I got the code pulled and was told that it was a o2 heat circuit problem. I turned the key to the on postion and checked for voltage. Which two pins do you use to read the resistance.
Expert:  RIP replied 9 years ago.

Michael,

It's very common for the o2 sensor's heater to fail and cause this code. On the sensor, depending on what brand it may be, there will be two identical colored wires of the four. There may be (2) white, (2) black, etc. These are your heater wires. Commonly, if you place the meter in ohms, and measure across them while the sensor is disconnected, it will show an open circuit (no reading). This will confirm the oxygen sensor repalcement. Now, if there is another reading, let me know what it is and i'll look up the specification.

-Rip

Customer: replied 9 years ago.
2 black wires, green and a white. From black to black no resistance.
Customer: replied 9 years ago.
should there have been voltage across these to black wire on the engine side of the harness with the key on?
Expert:  RIP replied 9 years ago.

Perfect!, this means bad oxygen sensor. Now, be carefull of the one you purchase. The dealer is the best source but will cost you an arm and a leg. If you purchase aftermarket, or on the internet you may get a bad one, which may cause all sorts of new problems. So, whichever you decide to use, measure the new sensors resistance first, than if your engine runs different after installation, it will entail a defective unit. These sensors are very fragile and at the dealer thy're protected from damage, whereas in the aftermarket they're dropped on the floor, packaged incorrectly, etc. Let me know if you need help after you get the new one in. Also, it's easier and smarter to change the sensor on a cold engine, and make sure you keep the wires away from the exhaust manifold.

-Rip

Sorry, I got your second question a little late. Now, there are a couple of different methods Honda uses to power the heater. You should either have voltage on the engine side connector on the related wires, or connect your meter negative to ground and than probe each terminal with the Ignition on, you should read voltage.

 

RIP and other Honda Specialists are ready to help you
Customer: replied 9 years ago.
I checked from ground post two these to pins and there wasn't any reading. I just want to make sure that I don't buy a $200 o2 sensor and also have another problem, thanks
Expert:  RIP replied 9 years ago.

What about accross the terminals which the black wires would connect? It's rare to have both an open oxygen sensor and a fault in the wires or computer...let me know, thanks.

-Rip

Customer: replied 9 years ago.
Reply to RIP's Post: I just went and checked it again and found that I did have 11.8 volts from one of the black wire to ground, but not across them. The fluke meter that I was using, the probes must not have got to the pin the first time I checked it. And it's freezing outside, so I might have been shaking a litle.
Expert:  RIP replied 9 years ago.

Awesome...good job, it happens. That's what makes you a good technician, to double check your work. I think you'll be just fine after the replacement, and the best part is you saved a bundle on diagnostics.

-Rip

Customer: replied 9 years ago.
Reply to RIP's Post: Thanks for the help.
Expert:  RIP replied 9 years ago.

No problem, and thanks for the bonus, it's very generous.

-Rip

Customer: replied 9 years ago.
Reply to RIP's Post: I also added a bonus thanks again