How to Test the MAP Sensor Electrical Connector with a Jumper Harness and Scan Tool. This diagnostic trouble code (DTC) indicates that the upstream oxygen sensor for Bank 1, is producing a negative voltage (somewhere between 0 and -1 Volts [negative 1 V]). This reading is your current battery's voltage life. At this point, I'd just go through and do all the main stuff. After connecting the leads, start the engine until it's warmed up and reaches close-loop operation. Four wires, following the typical Bosch O2 sensor-side wire color format - the two wires colored alike are the heater circuit, the other two are for the sensor circuit. Step 2. Connect the red lead of the multimeter to the heater hot wire. If it's Bank 2 you are checking, you will need to check the same location of PIN C. The Bank 2 Silverado O2 sensor heate ground has a PURPLE wire with a WHITE stripe in it. Using a multimeter it is possible to test the resistance between the various pins of the wideband O2 sensor. Four wire O2 and A/F sensors have two differant circuits that are not directly connected inside of the sensor. engine temperature. When you turn the key on, do not start the engine. You should then set your digital multimeter by selecting a low range on the DC voltage scale. Mark : As this fault is concerning cat efficiency then it is the rear o2 sensor you should be testing. The sensor should not be hit, if it hits, the internal ceramic breaks and leaks and will stop working. Figure 5. To test the heater part all you need is a multi-meter. If the vehicle is warm and the 02 Sensor reading does not change, then there is a problem with the 02 Sensor and you can stop the test. with the scope/meter connected to battery ground. . The voltage should fluctuate between .40 and .60 volts rapidly. Lean air-fuel ratio. Turn the ignition switch of the vehicle ON without turning the engine of the vehicle on. 02104052 Intended For Nissan Sentra. Repeat these steps along the various sections of the circuit between the source and sensor to isolate the problem. 1. A: Gather the tools needed for the test: a burner and a multimeter. Crank and start the engine. 2. Disconnect the sensor. Check for faults in the wiring first. This is a very useful way to quickly see . Electrical check: In this case, it must be checked that there is no short circuit between the sensor and the housing or between the internal heating resistor (if it has the sensor). i've tested resistance of several denso-style o2 sensors and the heater circuit on each was between 6 and 12ohms, drawing about 1-2 amps on the heater circuit. 4. The other 2 pins are the pins that are used for the signal of the oxygen sensor. My preferred method is to spray carb spray into a vacuum hose. This test evaluates the operation of the Bosch LSU 4.2 oxygen sensor (pre-catalyst) in relation to the air-fuel ratio using the Volt Drop method. Step 5. Electrical check: In this case, it must be checked that there is no short circuit between the sensor and the housing or between the internal heating resistor (if it has the sensor). Turn the vehicle back on and check the reading on the voltmeter. . Start recording the sensor output. the mechanical condition of the engine. If it does not, replace the O2 sensor. Determine sensor signal polarity. Select the millivolt operation on the voltmeter. Crank and start the engine. Step 1. Poor fuel economy. Back probe the oxygen sensor heater's hot and ground wire. This can easily be done by spraying a little carburetor cleaner into the engine while it's running. Test the Oxygen Sensor Response to a Rich Fuel Condition. Now, set the voltmeter to look for 1 volt DC. The scope can also be connected to the sensor's heater wires to check the duty cycle of the heater circuit. This is the place to bosch wideband 5 wire oxygen sensor wiring diagram. You're probably thinking, "Duh!", but some test procedures will have you connected to the sensors floating ground . 3. Connect the black lead of the multimeter to the heater ground wire. 20 Votes) To check the MAF sensor's voltage signal and frequency, connect a voltmeter across the MAF voltage signal wire and ground wire. Disconnect and Remove the suspect o2 sensor using a 22mm wrench. If the multimeter does not register a reading, then there is something wrong with the wiring. Spray some penetrating fluid on to the oxygen sensor and allow a few minutes for it to soak. Step 1 - Once the oxygen sensor sensing wire has been located connect a volt meter to the feedback wire and ground The X-Series Wideband UEGO AFR Gauge has a user configurable display via buttons on the gauge face that allows you to change AFR values for different fuels, Lambda or O2%, change the center display to three or four digits, perform . STEP 1: First thing first, you want to closely take a look at the plastic housing of your sensor. 3. Step 2. Connect the DVOM positive probe to one of the sensor connectors and the other probe to ground. Let it run for about 15 minutes to get the O2 sensor to activate. Sensor 2 can be pre catalytic thus making Sensor 3 post catalytic To test, set the multimeter to resistance mode . 3. The combustion can be internal, as in a conventional vehicle or external combustion, as in a furnace or other device consuming . December 28, 2007. So, if the sensor is producing a negative . Step 4. Connect the volt meter negative lead to the black wire on the o2 sensor. Switch off the engine after obtaining the desired temperatures. On the lambda-sensor side, use the ohmmeter to measure the resistance at both cables for the heating element. CASE 1: The O2 sensor signal voltage moved up and down the as the engine idled. Reset the ecu (pull fuse method), then start with new plugs (unless you've changed them recently), regapped properly, set timing with jumper to 5BTDC, set idle at 750rpm, check TPS, warm up and check for codes, then do the test for the o2 sensor. Next, start and run the engine at idle until warm (about 15 minutes). For this, disconnect the connector to the lambda sensor. Put the o2 senor in the Vise or Vise grips. There is one (sensor 1) in front of the catalytic converter . Set the multimeter to test the circuit using the best scale available on your device. The . CASE 2: The O2 sensor voltage was stuck above 0.5 Volts as the engine idled. Checking the sensor itself requires a multimeter connected to the signal lead with the car running and I've . 98S, 2014 Impreza 5 dr Ltd (9 Subaru's since 1978, 7 were 5 sp) ILuvSubaru's. Save. Connect the negative black lead to a grounded point. 2)The new O2 has 2 browns, a purple and tan wire. Depending on the year of your 5.3 liter Silverado this wire might also be BLACK with a WHITE wire. An oxygen sensor must be warm before it will operate properly Bosch LSU4 0 with a P2270 trouble code Engine Performance Diagnostics chapter 5 page 23 0 with a P2270 trouble code Engine Performance Diagnostics chapter 5 page 23. . If not, check the connections. You should see a square wave pattern and a decrease in the duty cycle as the engine warms up. Depending on your vehicle model, your engine might experience one or more of these performance problems: Rich air-fuel ratio. You have to check every wire this way. Place your multimeter in Volts DC mode and: Connect the Red Multimeter Lead to Battery Positive (+) Terminal. This powers the sensors in your engine bay, but do not start your car. A: Gather the tools needed for the test: a burner and a multimeter. The first two are the pins that are wired to the heating element. Connect multimeter to terminals 2 + 6 of connector to control module for Diesel-Direct fuel injection system for voltage measurement. Those leads are often white. Let it run for about 15 minutes to get the O2 sensor to activate. Look to the sensor side of the connector. The white ECM goes to the purple, black to brown, red/yellow to brown and orange/black to tan. This step will check to see if the wiring from the sensor is properly grounded. You first need to check the voltage supply and ground on pins 2 and 4. 2. To check the sensor operating correctly, you have two tests to run. Block the duct opening leading to the engine with a clean rag. Disconnect the plastic duct from the air cleaner assembly on your vehicle. High input means open circuit, and when you remove the sensor you get the same thing. You will see 5, 7, or 12 reference volts depending upon the car. Nominal heater cold resistance at 20C. Using your digital multimeter, you will need to probe the ENGINE side of the harness at PIN C as shown. Mark : This should be 12v. fuel quality. Step 7. If the multimeter registers a reading, your circuit wiring is intact. The reading should fluctuate rapidly. Check oxygen sensors: I have ordered for two new upstream sensors and done tests for the two downstream sensors. Turn on the ignition without starting the engine. Check wire harness or connector (oxygen sensor - EFI relay): I am stuck here also. Two wires connect to an external heater which is often less than 10 ohms. 6. This, I believe corresponds to a 14.7 air to fuel mixture. 3)The instructions it came with say connect blue to Signal wire, two blacks to to either heater wires. Wideband o2 . 4.6/5 (6,543 Views . With the digital volt ohm meter or DVOM in the 20K ohm position, connect the positive DVOM lead to the sensor's center terminal. Step 4 - Use a Multimeter. If the O 2 sensor heater circuit's negative wire goes directly to ground, look for a short-to-power problem. I have 5 wires in the harness heading to the sensor and 6 wires at the chasis side of Use Bosch, or NGK and you will be fine. The sensor should go between a certain range to show it is working properly, usually fluctuating between 100 mV and 900 mV. Open the bonnet of the vehicle and locate the O2 sensor. 4 wire sensors have been used for a while so it is easy to find them at junkyards. Then you must connect the red wire and the black wire. The sensor should not be hit, if it hits, the internal ceramic breaks and leaks and will stop working. In case the heater wires of the O2 Sensor in your car are working well, the readings you will see on the Digital Multimeter should have some value between 10 Ohms to 20 Ohms. Test the fuse and relay first and then perform the amperage draw. If the readings of the sensor output somehow appear in the middle, then the upstream O2 sensor is faulty. Step 3. You will need to get your multi meter to read in a resistance in ohms.