My 1999 Lexus Es300 had 8 codes. 2 old ( both knock sensors, both have been replaced along with the wiring harness). Yesterday car started to smell faintly of gas fumes. Today car was running fine , then at stoplight it started to idle rough and stumble. And 6 new codes along with it. P0120, P0441 (shows this code twice), P0300, P0304 and P0305
The 3 p0300 codes are all misfire codes. P0300 is a multiple misfire code and P0304 is cylinder # 4 and P0305 is cylinder #5. Could be a blown head gasket or a glitch if it continues after trying to reset codes and test. As for the other codes I have outlined there meaning below. The P0441 will not effect drivability so I would concentrate on the other codes first.
Code P0120 – Throttle/Pedal position sensor/switch “A” circuit malfunction
Code P0120 Description
The throttle position sensor is mounted in the throttle body and detects the throttle valve opening angle. When the throttle valve is fully closed, a voltage of approximately 0.7 is applied to terminal VTA and the ECM. This voltage increases in proportion to the opening angle of the throttle valves and becomes approximately 2.7 ~ 5.2V when throttle is fully open. The ECM judges the vehicle driving conditions from these signals input from terminals VTA and uses them as one of the conditions for deciding the air-fuel-ratio correction, power increase correction and fuel-cut control etc.
HINT: If DTCs P0110 (Intake Air Temp. Circuit Malfunction) and P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/Pedal Position Sensor/Switch ”A” Circuit Malfunction) are output simultaneously, E2 (sensor ground) bay be open. Read freeze frame data using LEXUS hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining whether the vehicle was running or stopped, the engine warmed up or not, the air-fuel ratio lean or rich, etc. at the time of the malfunction.
Code P0441 – Evaporative Emission Control System Incorrect Purge Flow
Code P0441 Description
The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evaporative emission control system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components within the dotted line in fig. 1 below, or when there is a malfunction in either the VSV for EVAP, the VSV for vapor pressure sensor, or in the vapor pressure sensor itself.
Car was throwing knock sensor codes P0325 and P0330. Check engine light on. Car radio intermittently goes off then comes back on and when that happens dash lights will sort of flicker and if headlights are on, they will turn off then comes right back on. Replaced both sensors and wiring harness. Found a rats nest underneath the intake manifold. After replacing sensors and harness, codes are still there but with them are now P0171 and P0420.
I would start by looking at all the wiring at and around the area you found the nest. Then look around other areas specifically around the ECM wiring harness. I think the P0171 is being caused by an intake leak and at the same time influencing the P0420 code. I have added the code information below.
Where is the tone ring or reluctor ring located for the left front speed sensor is it in the wheel bearing or on the half shaft?
Did some research on the internet and through several auto repair manuals to reach no exact answer. An actual visual inspection will be necessary for this one. Follow the speed sensor wire to its location at the wheel.
According to Amazon the correct hub bearing does not have the speed sensor & internal ring.
However theMitchell Manual diagram indicates shows the speed sensor and ring internal with only and external plug.
The Motor Manual shows the vehicle calls for part#89542-30270 which would require an external speed sensor ring. Usually found on the cv-shaft, rotor or back of hub bearing.
Chilton Manual had no useful information in regards to this question.
Looked up the parts for the AWD at Lexus Site: MYLparts.com and it appears the external ABS Speed sensor ring would be external.
A few weeks ago my 1999 Lexus RX300 started running rough and using more gas than usual. The check engine light had been on since I bought it in
September but there had been no issues before this. Took it to Advance Auto and had the computer scan done, Cylinder 1 and 6 misfires. Replaced
all coils and spark plugs, reset the light. Ran good for about 3 days then it was hard to start and keep running, figured it was cold natured and began
warming it up for 15 minutes or more before driving. A couple more days later the check engine light flashed a few times, car acted like it had died (no
power and seemed to have cut off), then the car was shaking and acted like it had been shifted down suddenly (transmission revving and RPms racing).
My dad ran a scan on it, but no codes or anything show up. The check engine light only comes on during these episodes, which last only a few
seconds, and seem to happen more when it’s cold (the weather or the car) and when I take my foot off the gas pedal to slow down. What could be
My initial guess without looking at it would be the Intake Air Hose is loose. Check for loose hose clamps from the engine air cleaner/filter assembly that connects to the MAF Sensor. Or a loose hose at or around the MAF Sensor. Probably got knocked loose or accidentally left loose when it was worked on.
Using the wiring diagram provided you can see there is a main fuse and relays involved. Check those first before moving on to checking the combination switch. The combination switch would be the most common failure component.
The headlights and fog-lights are controlled by the combination switch. This switch signals the the Body ECU to activate the headlamp relay. The headlamp relay receives its battery power from a 50amp “Main Fuse” that is hot at all times. The fog-lights and headlights have separate relays along with DRL relays. I wouldn’t think all the relays went out at the same time. I would rather suspect the switch, the fuse or the ECU. You may use the provided wiring diagrams to help better understand the circuit.
Headlight Wiring Diagram (1 of 2) 2001 Lexus RX300
A strange problem I notice is that on a slightly hard kick down on the accelerator the tachometer rises and remains at above 3000rpm for speedometer of 60mph. The rpm keeps rising with increasing mph. The engine never seem to settle with increasing acceleration until I turn it off and restarted. But on gradual accelerator kick down rpm calms down with various gear shifts and reaches 3000rpm for speeds of 100mph and above. What could be the problem? I also notice this mostly when the ac is on. Overall the acceleration is tepid.
Strange. Almost sounds like the torque converter clutches are slipping or something.
Hey… I have a question regarding the Lexus knock sensor in a 2001 Lexus ES300 V6 3.0L. Is there a difference between knock sensor bank 1 and 2? Can I use the knock sensor from bank 1 on bank 2?
Yes. You can use the knock sensor from bank 1 on bank 2. The two sensors have the same part number: KS159 and run about $140 each. There is no difference at all since the part numbers are the same. So if there is a benefit for you then go ahead and swap away.
Knock Sensor Location
Both knock sensors are located underneath each engine cylinder head assembly. They are mounted in the engine block. I recommend using a SST Socket number 09816-30010 hence making it easier to remove.
The electronic key will not lock and unlock the doors. When held up to the start ignition button the car cranks properly. However, once it’s cranked the “cannot detect key” prompt comes on. I have replaced the battery in the key.
This can happen if you have a cell phone or other RF device close to your key, it interferes with the communication between the car and the key. Is it both keys(fobs)? Switch batteries between the fobs and see if the problem follows the battery.
Cannot Detect Key System Description
1. ENGINE IMMOBILISER SYSTEM DESCRIPTION
(a) The engine immobiliser system determines whether or not to disable starting of the SFI system based on a comparison of the key‘s ID codes and the vehicle’s pre-registered code. The engine immobiliser system compares the vehicle certification ECU’s pre-registered ID code with the key-embedded transponder chip’s ID code. If the ID codes do not match, the engine immobiliser system activates and the SFI system cannot be started. The certification ECU manages communication with the SFI system, main body ECU (driver side junction block), steering lock ECU and ID code box. When the ID codes of the transponder chip and certification ECU match, the certification ECU authorizes the starting of the SFI system.
2. FUNCTION OF MAIN COMPONENT
Transponder key coil/amplifier (built into engine switch)
Receives key ID code, amplifies ID code and outputs it to certification ECU
Indoor electrical key oscillator
Transmits key detection signals within detection area in vehicle interior upon receiving transmission request signal from certification ECU.
Certification ECU request signal is activated when key is brought into vehicle interior and engine switch is pushed.
Door control receiver
Receives ID code from key in actuation area and transmits it to certification ECU
Security indicator light
Illuminates or starts blinking.
Illumination is controlled by front multiplex network door ECU.
3. SYSTEM FUNCTION
(a) Using entry function
(1) When the driver (or passenger) is sitting in the vehicle while carrying the key, and the brake pedal is depressed while the engine switch is pressed, the main body ECU (driver side junction block) recognizes that the engine start operation has occurred and sends a certification request signal to the certification ECU. Upon receipt of the certification request signal, the certification ECU sends a request signal to the indoor electrical key oscillator. Upon receipt of the request signal, the indoor electrical key oscillator sends a request signal to detect if the key is inside the vehicle. When the key receives this request signal, it answers by sending an ID code containing a response code through the glass antenna to the door control receiver. Upon receipt of the ID code, the certification ECU analyzes the code. If the interior certification passes, then the main body ECU (driver side junction block) sends a certification pass response signal. When the main body ECU (driver side junction block) receives this signal, the ACC relay is switched on and the IG1 and IG2 relays are switched on in sequence after 0.025 seconds. At this time, the engine switch indicator illuminates in green. Then the certification ECU checks that the power source mode has been changed and sends a steering lock command signal to the main body ECU (driver side junction block). After receiving this signal, the main body ECU (driver side junction block) supplies power to the steering lock actuator. Then (via the ID code box) the steering lock ECU confirms that the certification ECU is certified and drives the steering actuator’s motor until the steering lock is unlocked. After unlocking the steering lock, an unlock completed signal is sent to the certification ECU. Upon receipt of this signal, the certification ECU sends an unset command signal to the ID code box. Once this signal is received, the ID code box confirms that the certification ECU is certified, sends an immobiliser unset command signal to the SFI system and sends a security indicator light off signal to the front multiplex network door ECU LH and RH.
(b) Not using the entry function (when battery is depleted, affected by wave noise, etc.)
(1) When the driver is sitting in the vehicle while carrying the key and the brake pedal is depressed, the main body ECU (driver side junction block) recognizes that the stop light switch is on and sends a key confirmation request signal to the certification ECU. Upon receipt of this signal, the certification ECU drives the motor of the engine switch’s built-in immobiliser amplifier. At this time the engine switch sends an RF wave communication signal to the immobiliser. If the driver holds the key up to the engine switch at this time, the engine switch receives the immobiliser RF wave signal and responds by sending a radio wave signal. When the engine switch receives the radio wave signal from the key, it duplicates the signal and sends an ID code to the certification ECU. Upon receipt of the ID code, the code is analyzed. If the certification passes, a key certification pass response signal is sent to the main body ECU (driver side junction block) while simultaneously sending a sound buzzer request signal to the meter ECU. When the main body ECU (driver side junction block) receives this signal, the ACC relay is switched on and the IG1 and IG2 relays are switched on in sequence after 0.025 seconds. At this time, the engine switch indicator illuminates in green. Then the certification ECU checks that the power source mode has been changed and sends a steering lock command signal to the main body ECU (driver side junction block). After receiving this signal, the main body ECU (driver side junction block) supplies power to the steering lock actuator. Then (via the ID code box) the steering lock ECU confirms that the certification ECU is certified and drives the steering actuator’s motor until the steering lock is unlocked. After unlocking the steering lock, an unlock completed signal is sent to the certification ECU. Upon receipt of this signal, the certification ECU sends an unset command signal to the ID code box. Once this signal is received, the ID code box confirms that the certification ECU is certified, sends an immobiliser unset command signal to the SFI system and sends a security indicator light off signal to the front multiplex network door ECU LH and RH.