Category: P0138 and p0140

P0138 and p0140

This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. The O2 sensor for Bank 1, Sensor 2 does not respond does not have a voltage change between mV to the fuel cutoff or fuel enrichment signals from the ECM for more than 74 seconds. The ECM loses the ability to keep the fuel system air-to-fuel ratio correct could cause erratic driving symptoms.

Follows the manufacturer's specific pinpoint tests for further diagnosis of the code tests differ between manufacturers. The no response of the O2 sensor can be caused by a mass airflow sensor being contaminated and not calculating the amount of air entering the engine on the intake side.

This code can be due to problems with the mass airflow sensor, which is needed to calculate the proper amount of air entering the engine. The ECM can lose control or get the wrong input from sensors like the mass airflow sensor or the O2 sensor if they are within specification but incorrect. The no response of an O2 sensor may be due to a mass airflow sensor that is contaminated from things like oil from an oil impregnated air filter, as is common to all sensors.

This oil coats the sensor and can cause it to become inaccurate. Cleaning the sensor may or may not fix the problem. YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at With YourMechanic you can skip the auto shop altogether.

P0138 OBD-II Trouble Codes: O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)

They send certified and screened mechanics straight to your door and enable you to save big on car repair and maintenance. Cost of diagnosing the P code. No more waiting rooms!

Cc to hp calculator

Our mechanics will come to you to diagnose and fix the P code. Recent Check Engine Light is on Inspection reviews.

Error Code P0140: 02 Sensor Circuit No Activity Detected Bank 1 Sensor 2

Excellent Rating. Average Rating 4. Number of Reviews 5, Rating Summary. Johnathon 8 years of experience. Request Johnathon. Johnathon was on time and was very knowledgeable. Going to use in future. Travis 12 years of experience. Request Travis. Fair, honest, punctual, and knowledgeable. I was also to get back up and running for less than I thought.Theoretically you can drive for a few weeks or even months with a broken MAF sensor.

You will notice a decrease in gas mileage and over time the car will eventually start stalling a lot.

Iam policy json example

So you should chech it on our car models. The crankshaft sensor signals the fuel injection computer or the ignition control when the cylinders are firing. This causes the ignition coil to provide a spark and the injector to inject fuel into each cylinder at the right time. If either sensor isn't working correctly, the car will run rough and the engine will be less efficient. In later car models, the car's computer can usually keep the vehicle running, but the engine warning light on the dashboard goes on to warn the driver.

Parts or components should not be replaced with reference to only a P DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing. Code Search Please fill the "Code Box" to find engine fault code. Ways to read engine trouble codes. Ways to clear check engine light on car panel. Check Engine Light Dictionary Ways to clear check engine light on car panel. Main engine trouble code archive on Web.

Copyright EngineTroubleCode. Check engine light comes on Engine stalling or misfiring Engine performance issues Car not starting. If one of these reasons for P code is occuring now you should check P repair processes.

P1060. P0140 02 sensor circuit no activity detected bank 2 sensor 2 bank 2 sensor 1 chevy tahoe 2002

Now don't ask yourself; What should you do with P code? The solution is here :. For optimum catalyst operation, the air fuel mixture air-fuel ratio P code.This indicates there is a failure to have a low voltage output below 1. The O2 Sensor could be functioning improperly, or there could be a lack of continuity in the wiring to the ECU, or it is possible that power is not supplying sufficient enough voltage to the sensor.

This sensor monitors oxygen levels in the exhaust stream. In order to check the O2 Oxygen Sensor Circuit High Voltage Bank 1, Sensor 2, the scanner will show the P code, which indicates the error, and the following should complete the checklist:. Fouling would indicate a rich fuel mixture of more fuel than oxygen. This could cause fouling of the O2 sensor.

Oil or coolant from an engine leak making its way into the exhaust system could be another cause for fouling.

Cell phone cases for samsung galaxy note 8

Check for damage to exhaust pipes and catalytic converter. Check wiring harness for melted wires especially near hot exhaust parts. Do a visual check of the connections as well as using a Volt Ohm meter for wire connections. Another cause could be a damaged or clogged catalytic converter. A leaking fuel injector could possibly be another cause.

Mcmmo blackspigot

The number one most common repair for this problem is replacing the O2 Sensor itself. Another repair would be to replace the wiring or connection for Bank 1, Sensor 2. If the catalyst is the problem, replace the catalytic converter. Replace the fuel injector if it is leaking. After repairs have been made, clear stored codes from the ECU and test drive the vehicle between miles per hour for about two miles.

p0138 and p0140

If the Oxygen O2 Sensor signal ever goes to a negative voltage, or in excess of one volt, this is indication that the sensor is bad. These inconsistent readings are often the reason to believe the circuit is losing voltage or ground into the O2 Sensor circuit.

If the O2 Sensor body has a chalky appearance, this indicates lag between phases and should be replaced. Remember me. Table of Contents. Subscribe to our mailing list.Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins. What does this mean? Cost of diagnosing the P code Labor: 1. The auto repair labor rates vary widely across the country, and even within the same city.

When is the P code detected? The P code is set when the voltage signal sent from the sensor to the Engine Control Module is constant.

P Meaning The heated oxygen sensor 2 HO2Safter three way catalyst manifoldmonitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture air-fuel ratio must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The HO2S generates a voltage between 0. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich.

P More Information Need more information on how to fix the P code? Get Access to Factory Service Manuals.

p0138 and p0140

Related Information. Repair Importance Level: 2. Why is the Engine Light ON?We recommend Torque Pro. Oxygen sensors play a critical role in the fuel, ignition timing, and valve timing strategies calculated by the PCM. On most applications, the PCM provides a baseline signal voltage of around millivolts when the sensor is cold.

P0140 OBD-II Trouble Code: O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 2)

As the heater control circuit warms up the sensor element to bring the sensor into operation sooner, the resistance which is generally about 8 Ohms starts to drop, which allows the sensor to generate signal voltages that are based on the amount of oxygen in the exhaust stream. If the PCM detects that it takes longer than about 60 seconds or so for the sensor element to heat up, or that the signal voltage does not move outside of theto millivolt range, it will deem the oxygen sensor to be inactive, set code P, and trigger the CHECK ENGINE light.

Note however that the values given here are guidelines only; consult the manual for the vehicle being worked to get the exact values for that vehicle.

Adesso ci sono i computer...

This type of sensor is NOT interchangeable with conventional oxygen sensors; consult the relevant manual for the correct diagnostic, testing, and repair procedures that pertain to this type of sensor. The panel below illustrates some of the causes of P that are not related to wiring, or other electrical issues. Damage to wiring in the heater control circuit that could influence the time it takes a sensor to reach working temperature — about 0 C.

Blown fuse s in the heater control circuit where applicable that prevents the element from heating up. Failed, or failing PCM. Note that this is a rare event, and the fault must be sought elsewhere before any controller is replaced. On the other hand, some symptoms may be so severe on other applications that the vehicle becomes undriveable; also be aware that the severity of one or more symptoms may vary between vehicles.

Possible symptoms include the following. NOTE 2: Before attempting an electrical diagnosis of code P, make sure the engine is in good running condition, and that no vacuum- or serious exhaust leaks are present that could influence the operation of oxygen sensors. Also, make sure there are no rich- or lean running conditions, and that the engine oil is not contaminated with antifreeze.

If any other codes are present along with P, resolve these issues first before trying to diagnose P NOTE 3: In a properly functioning oxygen sensor, any change in the throttle setting will produce an almost immediate change in the signal voltage; however, the speed at which the changes occur as a function of sensor efficiency can best be judged with the use of an oscilloscope.

Bear in mind though that while an oscilloscope can identify incipient problems, the interpretation of waveforms produced on oscilloscopes requires expert knowledge and verified reference data for each application being tested. Therefore, for the purposes of identifying a defective oxygen sensor if an oscilloscope is not available the fact that no change in the signal voltage occurs over a discernable period should be enough to confirm that an oxygen sensor is defective. Record all stored trouble codes and available freeze frame data.

This data could be helpful if an intermittent fault is diagnosed later on. Consult the manual on the function, routing, and color-coding of all associated wiring, and perform a thorough visual inspection of all wiring associated with the affected sensor. Look for burnt, shorted, or otherwise damaged wiring and connectors. Repair all wiring as required. If there is no visible damage to the wiring, perform resistance, input voltage reference voltageground, and continuity checks on all circuits associated with the affected sensor.

p0138 and p0140

Consult the manual on the exact values for the application being worked on, but be sure to disconnect the sensor from the PCM before starting continuity checks to prevent damage to the controller. Since code P indicates a problem in the signal voltage circuit, as opposed to the heater control circuit, pay particular attention to the resistance and continuity values in the signal circuit between the PCM connector and the sensor. These values should match those stated in the manual exactly.

P0140 – Heated oxygen sensor (HO2S) oxgen sensor (O2S) / 2, bank 1 no activity detected

However, avoid making repairs to the signal circuit- the better option is always to replace the relevant harness to prevent issues with bad connections and high resistances that could result from poorly executed repairs. Make all repairs required to ensure that the sensor receives full battery voltage. Be aware that on some applications, the heater circuit voltage is supplied by the PCM, in which case the circuit is not protected by a fuse.

Consult the manual on how the heater input voltage is delivered to the sensor. NOTE: Since the sensor has a heated element, it is entirely possible that a low battery voltage, poor battery ground, or other continuity issues could affect the time it takes the element to heat up, which is one of the causes that could set code P Follow the testing procedure outlined in the manual to check that full battery voltage reaches the sensor.Error P code is a bank 1 error that indicates a malfunction with the rear oxygen sensor, also known as the post catalytic converter.

The oxygen sensor O2 sensor that is located on bank 1, sensor 2 relies on a 0. When this voltage is exceeded or not met, the O2 sensor misreads the amount of oxygen in the exhaust. This results in a sensor malfunction or failure. The readouts from this sensor are used in vehicle emission tests; a faulty test can cause the vehicle to fail these tests.

While the issue in itself is minor, it may be indicative of a more serious problem within the fueling or exhaust system.

Wilwood hydraulic clutch conversion kit

It may also lead to more frequent or serious issues involving the engine. While a sensor failure may sound major, it is in fact a natural part of the vehicle life cycle; sensors will inevitably fail and need to be replaced as the vehicle continues to be operated over time.

Error P can be diagnosed fairly easily. With the engine on and in warm-up mode, use a scan tool and specifically pay attention to voltage data from the bank 1 sensor 2 O2 sensor.

If the sensor is working correctly, there will be a gradual back and forth switch above and below 0. If the voltage has become stuck at one value, then there has been a malfunction. The surrounding harnesses and wires should also be checked for signs of melting. Similarly, the ECM should be checked to rule out that it has malfunctioned as well. If a sensor malfunction has been diagnosed and verified, the best course of action is to replace the faulty O2 sensor at the earliest convenience.

The same goes for the ECM if it has proven to be faulty. Remember me. Table of Contents. Subscribe to our mailing list.Bank 1 indicates that the sensor is on the side of the engine with cylinder 1 in the firing order. Sensor 2 monitors emissions after the catalytic converter. Look up which side of the engine bank 1 is on.

It uses this data to tune the engine on the fly. The PCM supplies a voltage or roughly. As the engine warms up, this voltage is supposed to change.

p0138 and p0140

Most of the time, the only symptom of P is going to be the service engine soon light. This is due to the fact that sensor 2 monitors exhaust emissions. There are a lot of different things that can cause P to be thrown in the Equinox. Here is a list of common potential causes for P in general:. The wiring harness often goes bad with the 02 sensor by the catalytic converter. The extreme heat from the exhaust can really damage a wiring harness, espescially the connection.

There are a lot of issues that can cause P in the Chevy Equinox. If you feel there is anything that you could do to improve or add to this article, please leave a comment below. Make sure that the pins look good and that the harness is seating well and not cracked. Also check to make sure that the wiring is not frayed or shorted.

How to check for a short YouTube. Bad O2 Sensor — The oxygen sensor itself can go bad. This is often the cause of P Exhaust Leak — An exhaust will can cause P You should be able to listen and find it. Bad Heated O2 Circuit The wiring harness often goes bad with the 02 sensor by the catalytic converter. Conclusion There are a lot of issues that can cause P in the Chevy Equinox.

thoughts on “P0138 and p0140

Leave a Reply

Your email address will not be published. Required fields are marked *