P0135 Vs P1135

[Gruss]

I am getting a P0135 on my '03 RX300.

Everything I have read indicates a heater problem on the B1S1 AF Sensor.

However, it appears I should be getting a Lexus-specific P1135 instead of the SAE P0135.

(I am getting this code from a Davis CarChip in my OBD-II socket).

Anyone have any clues as to why I am seeing P0135 instead of P1135?

I plan to replace the AF sensor anyhow; just curious.

Thanks

[code58]

I am getting a P0135 on my '03 RX300.

Everything I have read indicates a heater problem on the B1S1 AF Sensor.

However, it appears I should be getting a Lexus-specific P1135 instead of the SAE P0135.

(I am getting this code from a Davis CarChip in my OBD-II socket).

Anyone have any clues as to why I am seeing P0135 instead of P1135?

I plan to replace the AF sensor anyhow; just curious.

Thanks

Not familiar with a Davis CarChip but it might be the sophistication (or lack of it) of the DCC. Since the P0135 lists 02 sensor and P1135 lists (Lexus specific) A/F ratio sensor and I'm sure , though you're from Pa., that by '03 they would definitely use A/F there rather than 02 on those sensors. Have you tried reading it with anything else? You do realize it's easy to check those sensors for failure of the heater? It very possibly is that because it seems to be the most common failure in those sensors, especially the rear one because excess heat seems to destroy them quicker back there.

[Gruss]

Thanks; I was going to check the heater resistance next; I put it up on ramps and am waiting for it to cool down.

How hard is it to get up there and disconnect the connector?

Do you really have to disconnect the battery? Everything I have read says you should do so, to avoid the risk of airbag deployment.

Seems overkill to me (and a pain to have to reset the radio, clock etc), and unplugging the sensor isolates it from the car's circuit.

Thanks.

[mikey00]

I wouldn't expect the Davis Car Chip to read a Lexus specific code. You could check with their tech support if you wanted to verify:

http://www.davisnet.com/support/help.asp

[Gruss]

Thanks;

It does read manufacturer specific codes from my Ford, but you could be right.

I am going to get a real scan tool.

[code58]

Thanks; I was going to check the heater resistance next; I put it up on ramps and am waiting for it to cool down.

How hard is it to get up there and disconnect the connector?

Do you really have to disconnect the battery? Everything I have read says you should do so, to avoid the risk of airbag deployment.

Seems overkill to me (and a pain to have to reset the radio, clock etc), and unplugging the sensor isolates it from the car's circuit.

Thanks.

The connector? Not real easy on the rear one. My suggestion is to have a friend lean over the drivers fender and reach behind the engine and hold the wire loom just where the sensor lead plugs into it. That way you can reach one hand up and release the tab and pull the plug out of it's socket. I did it alone but it is not easy because you can only get one hand up there at a time.

Forget what you've been told about disc. the battery. The only reason to do it is if you don't have a scanner to cancel the codes. There is NO danger of the air bags going off unless you're working directly with them, and then you need to disc. the battery for a while to let the system completely drain of any latent energy. The only time I have EVER discon. the battery for SAFETY is when I was working DIRECTLY with the air bag system or air bags. Good Luck!

[code58]

Thanks;

It does read manufacturer specific codes from my Ford, but you could be right.

I am going to get a real scan tool.

You may find that some of the scanners read MSC's for American cars, but not foreign.

[Gruss]

The connector? Not real easy on the rear one. My suggestion is to have a friend lean over the drivers fender and reach behind the engine and hold the wire loom just where the sensor lead plugs into it. That way you can reach one hand up and release the tab and pull the plug out of it's socket. I did it alone but it is not easy because you can only get one hand up there at a time.

Thanks for your help and suggestions; after a couple of hours of false starts and attempts at making custom tools, I finally managed it with the help of this grappler tool

(I recently bought it at Home Depot for something else). I attached the hooks to the sensor side of the plug; reached up with my left hand to press down the tab and jiggled the tool with my other hand. When I let go of the tab with my left hand, I didn't feel/hear the usual click so I was reasonably confident that the plug had moved enough so the latch didn't bite; I removed the grappler and I was easily able to remove the plug with my left hand. I was on a crawler with my head towards the front of the vehicle, which was on ramps with axle stands "just in case".

I put this much detail here so it might help someone else when searching for "rx300 how to disconnect rear af sensor connector"

Forget what you've been told about disc. the battery. The only reason to do it is if you don't have a scanner to cancel the codes. There is NO danger of the air bags going off unless you're working directly with them, and then you need to disc. the battery for a while to let the system completely drain of any latent energy. The only time I have EVER discon. the battery for SAFETY is when I was working DIRECTLY with the air bag system or air bags. Good Luck!

Thanks; I'll bear this in mind for the future. I ended up removing the battery anyway so I could get a clear shot to the front (Bank 2) sensor connector. I wanted a good understanding of the connector design before messing around in back.

The heater on the bank1 sensor is, indeed, open circuit; my 03 has 77k miles on it; seems a similar mileage to what many have experienced.

Next challenge is hoping the sensor is not seized; I put some WD40 on it and will probably let it set until the new one arrives.

Thanks for all the help here; I figure I saved myself a few hundred bucks (so long as I don't crack the manifold).

[code58]

Next challenge is hoping the sensor is not seized; I put some WD40 on it and will probably let it set until the new one arrives.

Thanks for all the help here; I figure I saved myself a few hundred bucks (so long as I don't crack the manifold).

Good morning Gruss- The WD-40 might do the job, and it might take something a little better suited to breaking rust. A suggestion I've made in the past that, I understand, won't do most people any good, is to use an ACETYLENE torch. (because most people don't have an acetylene torch) I used it for all the years I was in automotive work. I have NEVER had a rusted bolt or nut that would not yield to heating to a medium dull red and immediately removing. It breaks the rust bond and expands the nut away from the bolt. A life saver in rust country. They actually sell equipment now that operates on 110 AC V that heats very quickly by high speed magnetic pulse that does the same thing more safely. Can heat ANYTHING made of metal that is magnetic, and it's like magic! We had one at work and I loved it. Just take it easy, you sure don't want to damage the fitting- there is really no reason too. Good Luck!

[Domenico Nelli]

Thanks; I was going to check the heater resistance next; I put it up on ramps and am waiting for it to cool down.

How hard is it to get up there and disconnect the connector?

Do you really have to disconnect the battery? Everything I have read says you should do so, to avoid the risk of airbag deployment.

Seems overkill to me (and a pain to have to reset the radio, clock etc), and unplugging the sensor isolates it from the car's circuit.

Thanks.

The connector? Not real easy on the rear one. My suggestion is to have a friend lean over the drivers fender and reach behind the engine and hold the wire loom just where the sensor lead plugs into it. That way you can reach one hand up and release the tab and pull the plug out of it's socket. I did it alone but it is not easy because you can only get one hand up there at a time.

It took me a while to disconnect the B1S1 sensor wire from the harness. I wound up getting a mirror up there and shined a light to see what kind of connector it was. After determining that the tab was enveloped in the plastic connector housing, e.g. the tab was hidden in a cove so to speak. I used a little carb flat blade screwdriver and with my right hand, I tried guiding the screwdriver under the tab. Once I located it, I lifted the tab (with the screwdriver) and pulled on the wire simultaneously. This is how I finally released it. I did a lil dance in my driveway after it unplugged...

[code58]

It took me a while to disconnect the B1S1 sensor wire from the harness. I wound up getting a mirror up there and shined a light to see what kind of connector it was. After determining that the tab was enveloped in the plastic connector housing, e.g. the tab was hidden in a cove so to speak. I used a little carb flat blade screwdriver and with my right hand, I tried guiding the screwdriver under the tab. Once I located it, I lifted the tab (with the screwdriver) and pulled on the wire simultaneously. This is how I finally released it. I did a lil dance in my driveway after it unplugged...

That was worthy of a little dance believe me! :D