Hi , I need help please . Ok , I did search but I could not find a answer for me . My problem is , I bought a pair of o2 sensor from group buy , install them and they were working fine . Today , I service my car and check on the conzult , Both o2 sensor are dead : The Lh o2 sensor read 0.0V no matter I plug it or unplug it . So my question is , What could go wrong ? Is it possible the signal wire to ECU short ? What should I do to fix it ? cheers
Check that you have continuity through the o2 sensor wires. from the unit through the plug. Just to make sure that the connection is still good.
Check the engine control fuse in the engine bay fuse box. If it is blown, check your 02 wiring for shorts (often melted onto the exhaust/turbos)
Thanks for the help so far guys . A little update . RH side is Working now , but LH side still read 0.0V . I use this diagram to sort out the wire colour : The white colour will go to ECU , it read 0.0V on multimeter , black/red read 13.7V and black read 13.6V . Just to clarify , on Bosch o2 sensor , It has one black and two white . black one will connect to white on female plug and to ECU , and two white will connect to black and black/red wire , Is this correct ?
Thanks , Rh side i connect exactly the same and it work . But Lh side , still read 0.0V , when I swap black with black , one white on o2 sensor to white to ECU , conzult read LH side o.1V . what going on ? stumble .
A shorts o2 sensor After performing testing on my o2 sensor , I found it is dead . follow this article . Checking Oxygen Sensors on 300zx : Symptoms of bad oxygen sensors might be poor gas mileage or failing an emissions check. But there could be many other problems will also have those symptoms. Catalytic converters and oxygen sensors will not work as designed if not up to temperature. There are also adverse effects if the engine is running too rich. Running too rich can cause converters and sensors to get carbon fouled and shut down. After the rich condition is corrected, a hard run may be required to burn off the carbon and restore normal sensor/converter operation. A hard run may also be required after replacing bad sensors to clean out the converters. Cruising in a lower gear at 3000 rpm for 3 minutes should be sufficient to burn off the carbon. O2 Sensors provide optimal engine operation during cruise by sending the ECU continuous rich/lean signals used to control the fuel injectors. This is called closed loop operation. The ECU does not directly use O2 sensor signals during idle or at wide open throttle (open loop). Here the ECU program uses fuel maps along with other sensor inputs to control mixture. However the ECU does use O2 sensor signals to adjust the fuel maps. So in theory the O2 sensors do have an indirect effect on fuel mixture during idle and WOT as well as a direct input during cruise. Many good O2 sensors are replaced without first checking if they are still operational. Very often, sensors can last the life of the car if not damaged by contaminants. Most heated sensors will probably last at least 60,000 miles. Later versions will last over 100,000 miles. According to the service manual, an O2 sensor that is capable of providing the ECU with the proper signal (rapidly cycling between rich and lean) and has a properly functioning heater circuit does not need to be replaced. Nissan periodic maintenance does not require replacement of the oxygen sensor according to any time or mileage schedule. Those who demand optimum performance might decide to replace older sensors strictly because of age. This may or may not result in a noticeable change and may be totally unnecessary. NOTE: Any voltage or resistance checks should be done using a high impedance digital volt-ohm meter. Using an analog meter on a Z is definitely not recommended and could possibly damage the ECU, oxygen sensor, or other sensitive electrical components. Never check resistance at the oxygen sensor center terminal (white wire). It can damage the sensor. Shorting out the sensor center terminal to ground will not damage it. Shorting it to 12 Volts will kill it. With the connectors (1. and 2.) off, check for a resistance reading of 3 ohms to 1000 ohms on each sensor's 2 outer terminals. The oxygen sensor needs to be at the proper temp to give accurate rich/lean signal. The heater gets the sensor up to temperature quicker after a cold start. A cooler sensor runs richer. A burned out heater element will cause the car to run rich when cold but may still give satisfactory performance under highway driving conditions. Emissions tests can still be passed if sensor is hot. Running 2000 rpm for 2 minutes will help assure the sensor is up to proper temperature. A bad heater element may not be an urgent problem. The sensor may still function normally when the engine is fully warmed up. Note a bad heater circuit will not give a code 33/53. Check for more than 12 Volts across harness outer terminals with engine running. Black wire is ground. If OK, go to step 5. Otherwise continue. Note on later model cars, it is possible voltage may read zero with a hot engine. In other words the heater may be shut off by the ECU after the car is warmed up. With ignition on, check harness side for 12 volts (battery voltage) at one of the outer terminals (usually it's a red wire) while using the engine as ground. Power source is from Eng Cont fuse on the left fender fuse panel. If there isn't 12V at the connector, remove the fuse. Check which fuse terminal has 12V with the ignition on. Check harness continuity between the other fuse terminal and the connector's red wire terminal. Check for continuity (low resistance) to ground on the other outer terminal (black wire) with engine running. ECU will not provide ground to heater circuits unless engine is operating. To check the harness continuity, the ground source at the ECU is pin #115. If the oxygen sensors need to be replaced, there is information on sensor removal and related pictures in the FAQ titled, How do I gut my pre-cats? When all work is completed, remember to clear codes from the ECU. Refer to How do I perform ECU self diagnostics? Select Mode II to read codes. Then select Mode I to clear codes. Select again Mode II to confirm code 55. Note turning off ignition while in Mode II will cause ECU to retain error codes in memory. Also ECU reverts to Mode I when ignition is turned off.
Wiring issue Hi , my LH O2 sensor was shorts , so I replace it with new o2 sensor ( from group buy - bosch sensor ) . I wire the bosch O2 sensor to my old harness , and check it on the conzult , your beauty it work . Then , I went for a drive , but the car run like shit , hesitation from 1.5k to 3.5k ranger. disconnect the LH O2 sensor , car run smooth again . I , now drive the car with only one Rh O2 sensor . Could some one please tell me what wrong ? I rule out wrong tyre of O2 , because a lot of people here install it with out problem . Is it possible LH O2 sent the wrong signal to ECU ? and why ? Thanks
Hi . I have 300 zx TT euro spec and i have a very similar problem with 02 sensors. When i unlink 02 sensor( left or right side) ECU does'nt show any error . For example sometimes both sensors shows 0v on idle (consult).
Did you find out your problem? My jdm spec is showing 0 volts on lh 02 sensor it runs like crap but hesitate the same 1.5k and so on.
