Rx300 Code P1135
 

I have a 2002 RX 300. The Check Engine light came on along with Trac Off and VSC . Did a diagnostic check and had a P1135 code.

Because of the code I put in a new O2 sensor, the one between the firewall and engine. After the new sensor it still generated the same code. I checked the vacuum line behind the air filter and it is on properly. Gas cap is tight. Does anyone have any ideas on what the problem is?

Thanks

First, welcome to ClubLexus.

Second, I am referring to my 1999 RX300 Service manual on the following:

P1135- A/F Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

DTC Detecting Condition
When the heater operates, heater current exceeds 8 A (2 trip logic detection)

Trouble Area
-Open or in heater circuit of A/F sensor (bank 1 sensor 1)
-A/F sensor (bank 1, sensor 1) heater
-ECM

According to what I read afterwards, the easiest thing for you to do is to check the connections on the A/F sensor.

I would also suggest you clean off the A/F sensor and pull your negative battery cable to try to reset the code.

I put a new sensor in and got the same code.

Toyota/Lexus made sensor? Aftermarket sensor?

Bosch 13333

Some of the other part in the manual relates to checking the voltage on the MAF. It is rather complicated to show here and I don't have a scanner. I would put my suspicions on the Bosch replacement rather than the Toyota/Lexus part, becaue MAFs can be funny and are generally made for the car. I was told the one for the Camry will not work for some Lexus models and vice-versa.

Besides the P1135 code I do believe the engine is idling rough. If anyone has any ideas please reply. Thanks

Hello,
As you know, DTC P1135 mean A/F Sensor Heater B1S1 Circuit Malfunction.
I think need check resistance of heater Sensor (from Bosch).
For Toyota A/F Ratio Sensor (OEM Part No.89467-...) :
"...Using an ohmmeter measure the resistance between terminals +B and HT. Resistance: 0.8 - 1.4 ohms at 20°C (68°F). If the resistance is not as specified, replace the sensor..."
May be useful
http://www.babcox.com/editorial/us/us10226.htm
http://alflash.com.ua/o2calif.htm (old redaction)
HTH,
p.s. Sir,
You replaced Sensor1 on Bank 1 or on Bank 2?

Thanks alflash, I will get my ohm meter and check the resistance.

I replaced the one on the back side of the engine before the cat. According to what I read on the forum that should be bank 1 sensor 1, am I correct?
As an experiment I removed the sensor after the cat (left it plugged in, just took it out of the exhaust) to see what code was generated. No new code was generated. Does anyonw know what code the sensor after the cat will generate if it is bad.

Hi,
In my understanding, It is correct (change Sensor)
photo: http://alflash.com.ua/RX/_3442_1.jpg
Let us know the results of measuring resistance Bosch-sensor.
For check Cat ECM use down-stream oxygen sensor(s)
DTC: P0420 - Catalyst System Efficiency Below Threshold (Bank 1) and
P0430 - Catalyst System Efficiency Below Threshold (Bank 2)
Take a look http://alflash.com.ua/DLC/CAT10.gif (left is good Cat, Right - bad)
In [http://alflash.com.ua/DLC/Cat06.gif[/url] - screen Shot (for god Cat) for both Oxygen Sensors (Up-, Down-Stream) at Idle, Acceleration, and Deceleration.
For Sensor after Cat (Bank n Sensor 2) Toyota have these Codes:
P0037 - Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
P0057 - Oxygen Sensor Heater Control Circuit Low (Bank 2 Sensor 2)
P0137 - Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138 - Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0156 - O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 - Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 - Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2)
P0159 - O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
P0161 - O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
Note: Not all trouble codes are used on all models Lexus/Toyota.
Some codes is "Two-Trip Logic Detection")...
HTH,
p.s. You did Clear Memory after replacement? For example, by remove the EFI Fuse?
If no, remember, "the "Check Engine" lamp (aka MIL) may be deactivated after three subsequent sequential driving cycles during which the monitoring system responsible for activating the MIL ceases to detect the malfunction and if no other malfunction has been identified that would independently activate the MIL"
al.

OK, did the resistance check. I get a resistance of 0 which I would assume the sensor is bad.
On the front sensor I have a resistance of 1.1 ohms.

Hi,
Thanks for info.
Zero ohm resistance of heater this Sensor? OEM or new Sensor "from Bosch" ?
resistance must be >0.8 ohm...
All A/F Ratio Sensors are monitored for abnormal Heater condition. the ECM checks the amount of current required for the sensor heater. If the current is too high or to low a DTC will be set. The ECM provides a pulse width modulated control circuit to adjust current through the heater.
DTC P1135/1155 set when heater current exceeds 8A or heater current of 0.25A or less (2 trip detection logic.
I not sure, but may be need check wirings and connector...
1/2 OFF: See http://www.boschusa.com/AutoOrigEqui...xhaustSensors/
BR,

The 0 ohm is the original. I have already returned the Bosh13333 to the parts store where I purchased it so I can't check its resistance. I am curious to why it (the Bosch 13333) generated the code, I wonder if it was bad also. Thanks

One time I over filled my Tank and the VSC, Trac and Engine light came. on i was scared. so i called the dealer. immediately the he asked me if i tried to continue filling after the the pump shut off. i told him yes and he said it should come off in a day or 2 after i open the tank to let the gas fumes escape. And it did exaclty that.

anulex,

I have this problem in Mexico, but never had the lights come on. However, I did have a friend with a Murano with this issue. At Pemex stations (full service by law) they are taught to run up to the nearest 10 pesos, if it is says 375 pesos, they go up to 380 just to make extra $$$. I now stand there and block their hand from pumping any further as does my buddy.