Engine Code 1155

[mattbatson]

Okay, here is a quick synopsis of what has happened with my wifes' sisters 2002 rx300 with 150K miles...

First off, I've been working on cars most of my life and have a decent level of "car knowledge", but this has been a difficult

road since my sister in law doesnt know car's and I've had to try and pick her brain on the matter while I run my diagnosis, and it has been a rough

road.

Okay, she is driving down the highway on cruise control, goes to slow down for her exit, and the engine stays revved at around 2500 to 3K

rpm's. She comes to a stop at the light, and it is still doing it. She drives the 30 miles back home, with it doing this. Also the engine check

light is on.

She leaves it with me the next day. First thing I do is hook up my obdII scanner to run the codes. I also notice the VSC trac light is staying lit and the

center console button wont turn it off. I ask her about this and she says it is always lit and that the button is a "dummy" button.

I'm scratching my head on that one, but continue my diagnosis.

Scanner comes back P110, which is intake temp sensor. so I pull the MAF temp sensor and put on a new one. It still runs the same.

So I reset the ECU by disconnecting the battery neg cable. Still runs the same. However, NOW the VSC light is off, and I can turn it on and off with the

button, lol.

So I take the MAF sensor back to get my refund and put the old one back on. Now the rev's are rising and falling instead of just running at 3K.

I do another reset on the ECU, and now it is idling really low, like 3 or 400 rpm, and dies when backing out the driveway or coming to a stop.

So, I do some reading on here and find the IAC valve is a common dealeo. I take everything apart, clean it thoroughly, and as I'm putting everything back

together, I find a loose vacuum hose that connects under that plastic engine cover. I'm 100% certain I didnt accidentally knock it loose, as I'm very

careful and take my time, plus they are hard to pull off anyways.

So now I think I've got it cured, and go to start and it runs GREAT! Idle around 900, good power, perfect.

However, now I have another check engine light, which comes back as 1155, 02 sensor....

Could the 02 sensor be the problem? Even though now it runs great? I have tried reseting the ECU a few times, but this check light is still there.

[mattbatson]

Okay, here is a quick synopsis of what has happened with my wifes' sisters 2002 rx300 with 150K miles...

First off, I've been working on cars most of my life and have a decent level of "car knowledge", but this has been a difficult

road since my sister in law doesnt know car's and I've had to try and pick her brain on the matter while I run my diagnosis, and it has been a rough

road.

Okay, she is driving down the highway on cruise control, goes to slow down for her exit, and the engine stays revved at around 2500 to 3K

rpm's. She comes to a stop at the light, and it is still doing it. She drives the 30 miles back home, with it doing this. Also the engine check

light is on.

She leaves it with me the next day. First thing I do is hook up my obdII scanner to run the codes. I also notice the VSC trac light is staying lit and the

center console button wont turn it off. I ask her about this and she says it is always lit and that the button is a "dummy" button.

I'm scratching my head on that one, but continue my diagnosis.

Scanner comes back P110, which is intake temp sensor. so I pull the MAF temp sensor and put on a new one. It still runs the same.

So I reset the ECU by disconnecting the battery neg cable. Still runs the same. However, NOW the VSC light is off, and I can turn it on and off with the

button, lol.

So I take the MAF sensor back to get my refund and put the old one back on. Now the rev's are rising and falling instead of just running at 3K.

I do another reset on the ECU, and now it is idling really low, like 3 or 400 rpm, and dies when backing out the driveway or coming to a stop.

So, I do some reading on here and find the IAC valve is a common dealeo. I take everything apart, clean it thoroughly, and as I'm putting everything back

together, I find a loose vacuum hose that connects under that plastic engine cover. I'm 100% certain I didnt accidentally knock it loose, as I'm very

careful and take my time, plus they are hard to pull off anyways.

So now I think I've got it cured, and go to start and it runs GREAT! Idle around 900, good power, perfect.

However, now I have another check engine light, which comes back as 1155, 02 sensor....

Could the 02 sensor be the problem? Even though now it runs great? I have tried reseting the ECU a few times, but this check light is still there.

Update...

I used my scanner to erase the code and also rebooted the ecu with the neg battery terminal disconnect.

As soon as I restart it, after a few minutes, the engine check light comes back on, along with the VSC and trac off light on the dash...

I have no idea what the VSC light has to do with anything, but when the check engine light, but it is related somehow as it isnt on at first. But when the engine check light comes on, the VSC and trac lights on the dash also light up. And, as before, the code is still 1155.

Any ideas?

[code58]

Update...

I used my scanner to erase the code and also rebooted the ecu with the neg battery terminal disconnect.

As soon as I restart it, after a few minutes, the engine check light comes back on, along with the VSC and trac off light on the dash...

I have no idea what the VSC light has to do with anything, but when the check engine light, but it is related somehow as it isnt on at first. But when the engine check light comes on, the VSC and trac lights on the dash also light up. And, as before, the code is still 1155.

Any ideas?

Matt- Try removing the gas cap, take a look at the seal while you have it off and then re-install and make sure it's nice and tight. Then take a look at the hose on the back side (firewall) of the air cleaner and make sure it's installed properly to the back of the air cleaner. Next, go online to Amazon and order an A/F ratio sensor. (a lot of parts people, plain Joe's and even parts books call them an oxygen sensor). They are not, and an oxygen sensor WILL NOT WORK THERE! Amazon is the cheapest place I know to get them (around $100.) Or you can go to Toyota or Lexus and pay $250.- $300., your choice. You can disconnect the plug and test the sensor right on the car. Should be the 2 black wires from what I remember. All you have to do is test continuity with a DVM. Either way, doesn't matter because you're just testing continuity. If you have continuity, it's OK, no continuity, it's bad. The P1155 is SPECIFIC to the heater in the FRONT A/F ratio sensor. Has nothing to do with the A/F sensing itself, just the heater. That is the one that's easy to get to on the front pre-cat, just off the exhaust manifold. Test before you order, it's easy and it keeps the horse before the cart. The part on Amazon will be a Denso, who makes them for Toyota, just will have a Denso #, instead of a Toyota #. if you need more help, come on back.

[mattbatson]

Update...

I used my scanner to erase the code and also rebooted the ecu with the neg battery terminal disconnect.

As soon as I restart it, after a few minutes, the engine check light comes back on, along with the VSC and trac off light on the dash...

I have no idea what the VSC light has to do with anything, but when the check engine light, but it is related somehow as it isnt on at first. But when the engine check light comes on, the VSC and trac lights on the dash also light up. And, as before, the code is still 1155.

Any ideas?

Matt- Try removing the gas cap, take a look at the seal while you have it off and then re-install and make sure it's nice and tight. Then take a look at the hose on the back side (firewall) of the air cleaner and make sure it's installed properly to the back of the air cleaner. Next, go online to Amazon and order an A/F ratio sensor. (a lot of parts people, plain Joe's and even parts books call them an oxygen sensor). They are not, and an oxygen sensor WILL NOT WORK THERE! Amazon is the cheapest place I know to get them (around $100.) Or you can go to Toyota or Lexus and pay $250.- $300., your choice. You can disconnect the plug and test the sensor right on the car. Should be the 2 black wires from what I remember. All you have to do is test continuity with a DVM. Either way, doesn't matter because you're just testing continuity. If you have continuity, it's OK, no continuity, it's bad. The P1155 is SPECIFIC to the heater in the FRONT A/F ratio sensor. Has nothing to do with the A/F sensing itself, just the heater. That is the one that's easy to get to on the front pre-cat, just off the exhaust manifold. Test before you order, it's easy and it keeps the horse before the cart. The part on Amazon will be a Denso, who makes them for Toyota, just will have a Denso #, instead of a Toyota #. if you need more help, come on back.

Hey, phenomenal information Mr. code, I really appreciate it.

Okay, continuity test on the two black wires coming off the a/f sensor came back negative. No continuity. I'm assuming this means the sensor is bad and I can go ahead and order a new one?

Already soaking that sucker in penetrating oil, lol....

btw, I will be sure to post on here with results after replacing it...I find this is valuable info, as compared to people who post a problem, get suggestions on how to fix, and then never come back on to say if it is was the cure.

[mattbatson]

Update...

I used my scanner to erase the code and also rebooted the ecu with the neg battery terminal disconnect.

As soon as I restart it, after a few minutes, the engine check light comes back on, along with the VSC and trac off light on the dash...

I have no idea what the VSC light has to do with anything, but when the check engine light, but it is related somehow as it isnt on at first. But when the engine check light comes on, the VSC and trac lights on the dash also light up. And, as before, the code is still 1155.

Any ideas?

Matt- Try removing the gas cap, take a look at the seal while you have it off and then re-install and make sure it's nice and tight. Then take a look at the hose on the back side (firewall) of the air cleaner and make sure it's installed properly to the back of the air cleaner. Next, go online to Amazon and order an A/F ratio sensor. (a lot of parts people, plain Joe's and even parts books call them an oxygen sensor). They are not, and an oxygen sensor WILL NOT WORK THERE! Amazon is the cheapest place I know to get them (around $100.) Or you can go to Toyota or Lexus and pay $250.- $300., your choice. You can disconnect the plug and test the sensor right on the car. Should be the 2 black wires from what I remember. All you have to do is test continuity with a DVM. Either way, doesn't matter because you're just testing continuity. If you have continuity, it's OK, no continuity, it's bad. The P1155 is SPECIFIC to the heater in the FRONT A/F ratio sensor. Has nothing to do with the A/F sensing itself, just the heater. That is the one that's easy to get to on the front pre-cat, just off the exhaust manifold. Test before you order, it's easy and it keeps the horse before the cart. The part on Amazon will be a Denso, who makes them for Toyota, just will have a Denso #, instead of a Toyota #. if you need more help, come on back.

Hey, phenomenal information Mr. code, I really appreciate it.

Okay, continuity test on the two black wires coming off the a/f sensor came back negative. No continuity. I'm assuming this means the sensor is bad and I can go ahead and order a new one?

Already soaking that sucker in penetrating oil, lol....

btw, I will be sure to post on here with results after replacing it...I find this is valuable info, as compared to people who post a problem, get suggestions on how to fix, and then never come back on to say if it is was the cure.

is this the one?

http://www.amazon.com/Denso-234-9009-Oxygen-Sensor-Ratio/dp/B000C5YCZ2/ref=sr_1_5?ie=UTF8&qid=1305137285&sr=8-5

[mattbatson]

Update...

I used my scanner to erase the code and also rebooted the ecu with the neg battery terminal disconnect.

As soon as I restart it, after a few minutes, the engine check light comes back on, along with the VSC and trac off light on the dash...

I have no idea what the VSC light has to do with anything, but when the check engine light, but it is related somehow as it isnt on at first. But when the engine check light comes on, the VSC and trac lights on the dash also light up. And, as before, the code is still 1155.

Any ideas?

Matt- Try removing the gas cap, take a look at the seal while you have it off and then re-install and make sure it's nice and tight. Then take a look at the hose on the back side (firewall) of the air cleaner and make sure it's installed properly to the back of the air cleaner. Next, go online to Amazon and order an A/F ratio sensor. (a lot of parts people, plain Joe's and even parts books call them an oxygen sensor). They are not, and an oxygen sensor WILL NOT WORK THERE! Amazon is the cheapest place I know to get them (around $100.) Or you can go to Toyota or Lexus and pay $250.- $300., your choice. You can disconnect the plug and test the sensor right on the car. Should be the 2 black wires from what I remember. All you have to do is test continuity with a DVM. Either way, doesn't matter because you're just testing continuity. If you have continuity, it's OK, no continuity, it's bad. The P1155 is SPECIFIC to the heater in the FRONT A/F ratio sensor. Has nothing to do with the A/F sensing itself, just the heater. That is the one that's easy to get to on the front pre-cat, just off the exhaust manifold. Test before you order, it's easy and it keeps the horse before the cart. The part on Amazon will be a Denso, who makes them for Toyota, just will have a Denso #, instead of a Toyota #. if you need more help, come on back.

Hey, phenomenal information Mr. code, I really appreciate it.

Okay, continuity test on the two black wires coming off the a/f sensor came back negative. No continuity. I'm assuming this means the sensor is bad and I can go ahead and order a new one?

Already soaking that sucker in penetrating oil, lol....

btw, I will be sure to post on here with results after replacing it...I find this is valuable info, as compared to people who post a problem, get suggestions on how to fix, and then never come back on to say if it is was the cure.

is this the one?

http://www.amazon.com/Denso-234-9009-Oxygen-Sensor-Ratio/dp/B000C5YCZ2/ref=sr_1_5?ie=UTF8&qid=1305137285&sr=8-5

I found this on amazon ^^^^

and from everything I'm reading, it is for our 2002 Rx300. My only question is, is it for the one I'm replacing? Front of engine off header in back of radiator.

Or, is this sensor the same on that fits behind the motor next to the firewall? Same sensor for both locations?

[code58]

is this the one?

http://www.amazon.com/Denso-234-9009-Oxygen-Sensor-Ratio/dp/B000C5YCZ2/ref=sr_1_5?ie=UTF8&qid=1305137285&sr=8-5

I found this on amazon ^^^^

and from everything I'm reading, it is for our 2002 Rx300. My only question is, is it for the one I'm replacing? Front of engine off header in back of radiator.

Or, is this sensor the same on that fits behind the motor next to the firewall? Same sensor for both locations?

Same sensor, Matt. That is the correct one. If no continuity, it's history. Time for a new one.