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Horse4190

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Discussion starter · #1 ·
What does the P0141 code refers to, is it the same as the code for P0037?. Description for both are the same I think. I change my oxygen for my 2009 RAV4 when I got an error code of P0037. But now, the engine check/4WD camb back again with the new code of P0141. Anyone can help please. Tks.
 
OK, P0141: Oxygen Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

Causes:
1. Open or short in HO2 sensor heater circuit
2. HO2 sensor heater (bank 1 sensor 2)
3. Integration relay (EFI MAIN relay)
4. ECM

Code P0037: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)

Causes:
1. Open in Heated Oxygen (HO2) sensor heater circuit
2. HO2 sensor heater (bank 1 sensor 2)
3. Integration relay (EFI MAIN relay)
4. ECM

So they are quite similar. I would look for a wiring problem--chafed/burned wire, or a problem with the connector.
 
You'd need to determine if 12V is getting to the sensor. I believe it's across the two gray wires. If it's there and the connector looks good with no pins pushed out or bent I'd replace the sensor.
 
Thanks JuneBug. Do you think the problem is the connector of the newly installed Oxygen Sensor? And do I have to replace that again with the same new one?
It sounds like a wiring problem. As Dr. Dyno says, you need to check it with a voltmeter and/or ohmmeter. Make sure it's getting the 12V signal and the wire isn't grounding out against the frame.
 
Discussion starter · #6 ·
Thanks. I will check that and will see if 12V is getting it. Can I perform this checking whilst the whole oxygen sensor is inserted to the pipe? If that is possible, I will connect the red color of the ohmmeter to the gray or black of the sensor connector and the black goes to the ground. Is that correct?

Also, can I run the engine on whilst performing this test even though the sensor is not connected?
 
What brand sensor did you purchase? Just because it is new does not mean it is good.


I prefer DENSO sensors. They are the parts your Toyota was born with.


Since you have a different code related to the sensor, I suspect the sensor is faulty.
 
According to my 2006-08 wiring manual the 12V should be on one of the black wires and should be there with the ignition on, running or not. So, with your multimeter set on DCV, your connections are correct.

You can run the engine with the sensor in the pipe but disconnected.

Also from the Repair manual (available via Junebug's home page link) the sensor itself should measure 11 to 16 ohms between the black and red wires to the pins on the edge of the connector with 3 ribs.
 
Before I close the window the pinout for the sensor is in the 2006 RAV4 Repair Manual, 2AZ-FE Emission Control, Heated Oxygen Sensor.
 
Discussion starter · #10 ·
I just bought a multimeter to test. I hope this can be used as I cant find volmeter or ohmmeter. Just to confirm, I will set it to 20V and see if I can be achieved the 12V to test the new sensor I just installed?
 
It's strange that you'd be having this problem if you just replaced the sensor. I'm guessing you didn't buy a Denso part? You aught to just return the part and try another one.

I had this exact same error code a few months ago, and I replaced the sensor myself with a factory Denso part. No problems since then.
 
Discussion starter · #13 ·
Yes. The sensor I bought from ebay for $20 was not achieving 12V. I have removed this sensor again and tested with my multimeter and not getting any higher number than 0 signal. Since I do not have anything, I put it back again and will buy a decent one this weekend. Perhaps NGK is also recommended?? Denso is almost $213 Cdn from the dealer.
 
Not clear on how you did your test but I'd just buy another sensor from a different eBay seller. If you search you can find them with a lifetime warranty.
 
I just bought a multimeter to test. I hope this can be used as I cant find volmeter or ohmmeter. Just to confirm, I will set it to 20V and see if I can be achieved the 12V to test the new sensor I just installed?
Yes, that's how a multimeter is used. To check voltage, set the selector to the lowest range greater than the voltage you expect (20V to test 12V circuit). The black probe goes to ground - a clip really helps - and use the red to probe for voltage. Sometimes you can stick the pointed probe into the back of a connection without unplugging it. The meter will show about 12V when you contact power, probably 11.5 or so if the engine is not running, 13.5 or so if running.
 
Yes. The sensor I bought from ebay for $20 was not achieving 12V. I have removed this sensor again and tested with my multimeter and not getting any higher number than 0 signal. Since I do not have anything, I put it back again and will buy a decent one this weekend. Perhaps NGK is also recommended?? Denso is almost $213 Cdn from the dealer.
You might get away with NTK (NGK), but I have found that O2 sensors are extremely finicky and that the non-oem brands just do not "speak" with the ECU properly. One thing is for sure, stay away from Bosch O2 sensors in Japanese vehicles as they just do not work well.
 
Yes. The sensor I bought from ebay for $20 was not achieving 12V. I have removed this sensor again and tested with my multimeter and not getting any higher number than 0 signal. Since I do not have anything, I put it back again and will buy a decent one this weekend. Perhaps NGK is also recommended?? Denso is almost $213 Cdn from the dealer.
You're wasting your time with that volt meter. Put it away and buy a new part already.

LOL, you're crazy if you pay $200 for a Denso 02 sensor. They're less than half that price. Don't ever buy parts from the dealer unless you have no other choice. Go to Amazon, and buy a factory Denso sensor for $70. I've bought both the O2 sensors through the Amazon autoparts store and I had no problems. I doubt you'll find a cheaper, factory part price on Ebay.
 
It's strange that you'd be having this problem if you just replaced the sensor. I'm guessing you didn't buy a Denso part? You aught to just return the part and try another one.

I had this exact same error code a few months ago, and I replaced the sensor myself with a factory Denso part. No problems since then.
Just to want to be sure. If this the O2 sensor near the Oil-Pan? Thanks for a reply. Much appreacted.
 
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