Bosch Oxygen Sensor Electrical Schematic. Need supply volts, amps. Signal output voltage range. Heating element voltage and power requirements.

This code is for a post-catalyst oxygen sensor that isn't operating properly or not at all. The catalyst, or catalytic converter is used to control emissions. This particular o2 sensor on Bank 2, position 2 is after the converter on bank 2 and monitors the catalyst efficiency of the catalytic converter on that bank. The P.C.M (Power train Control Module) compares the post-cat o2 sensor to the pre-cat o2 sensors to measure the cat's efficiency. The o2 sensor is a four wire sensor. The P.C.M supplies a reference voltage to the sensor of about half a volt and also supplies a sensor ground. 12 volts are supplied for the heater element and also a ground for the heater element (the heater in the sensor helps the sensor to warm up faster which allows the engine to reach closed loop sooner). The sensor varies the reference voltage the P.C.M gives it based on oxygen content of the exhaust. The change in oxygen content causes resistance changes in the sensor which affects the 0.5 volt reference voltage. Oxygen sensors are capable of varying the supplied voltage between 0.1 volts to 0.9 volts. Lean exhaust produces low voltage and causes the supplied 0.5 volts to drop. Rich exhaust produces high voltage and causes the supplied 0.5 voltage to increase. Pre-catalyst (front) o2 sensors switch between low and high voltage rapidly one or two times per second. However this sensor is a post-cat o2 sensor and may switch much slower & not vary as much (this is normal). If the sensor "sticks" or there are too few switches in a given time period, P0160 may set.

The ASD relay supplies battery voltage (12+ volts) to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies 12-volts to the oxygen sensor heating elements. The Fuel Pump Relay is a separate relay controlled by the ASD relay input to the PCM. Fuse #12 (10amp) provides 12 volts to the coil side of both the relays and the ignition switch. Fuse #6 (30 amps) supplies 12 volts to the output side of the relay. Fuse #16 (15 amp) from the relay output to the Oxygen Sensors and Fuse #26 (15 amp) relay output to the PCM. Fuse #24 (20 amp) is Fuel pump relay output to fuel pump. Fuse #19 (10 amp) supplies 12 volts direct to the PCM.
look for burned or melted wires in the offending circuit.
sounds like you wiggled a wire while installing new relay.

I'm sorry you spent that money if this was the original code.

The code means one of the O2 sensors has a faulty heater or the power circuit for the heater is bad. The sensor is not heating up as fast as it should. Since you have replaced the sensor you would need to check the power circuit for the heater.

P0037 SUBARU Description Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module (ECM).

In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECM controls the heater element circuit by allowing current flow to ground.

The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.
Read more: http://engine-codes.com/p0037_subaru.html#ixzz26TjIZyLw

The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:

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• HOME
• REPAIR INFO
• 2001 JEEP GRAND CHEROKEE 4WD 4.0L MFI 6CYL REPAIR GUIDE
• ENGINE PERFORMANCE & EMISSION CONTROLS
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• THROTTLE POSITION SENSOR

Cherokee, Grand Cherokee, 1999-2005
Throttle Position Sensor

• OPERATION
• REMOVAL & INSTALLATION

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Operation

The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:


Ignition timing advance Fuel injection pulse-width Idle (learned value or minimum TPS) Off-idle (0.06 volt) Wide Open Throttle (WOT) open loop (2.608 volts above learned idle voltage) Deceleration fuel lean out Fuel cutoff during cranking at WOT (2.608 volts above learned idle voltage) A/C WOT cutoff (certain automatic transmissions only)

Removal & Installation

3.7L & 4.0L

1. Disconnect TPS electrical connector.
2. Remove TPS mounting screws.
3. Remove TPS.

To Install:
The TPS is mounted to the throttle body. The throttle shaft end of throttle body slides into a socket in the TPS. The TPS must be installed so that it can be rotated a few degrees. (If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs). The TPS will be under slight tension when rotated.

1. Install TPS and retaining screws.
2. Tighten screws to 7 Nm (60 inch lbs.) torque.
3. Connect TPS electrical connector to TPS.
4. Manually operate throttle (by hand) to check for any TPS binding before starting engine.

4.7L

1. Remove air duct and air resonator box at throttle body.
2. Disconnect TPS electrical connector.
3. Remove two TPS mounting bolts (screws).
4. Remove TPS from throttle body.

To Install:
The throttle shaft end of throttle body slides into a socket in TPS. The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.

1. Install TPS and two retaining bolts.
2. Tighten bolts to 7 Nm (60 inch lbs.) torque.
3. Manually operate throttle control lever by hand to check for any binding of TPS.
4. Connect TPS electrical connector to TPS.
5. Install air duct/air box to throttle body.

Hope this helps

P0044 - HO2S Heater Control Circuit High (Bank 1 Sensor 3)

The P0044 is set when the ECM detects an excessively high voltage through the heated oxygen sensor heater circuit

Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module (ECM).

In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECM controls the heater element circuit by allowing current flow to ground.

Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)

Possible causes
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit poor electrical connection
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit fuse
- Faulty Engine Control Module (ECM)

The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.



Hope helps (remember to rate this answer).

your o2 sensor is bad. vsc will go on for any small DTC displayed on the MIL (cel)

P0037 LEXUS P0037 LEXUS - Oxygen Sensor Heater Control Circuit Low Bank 1 Sensor 2 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
Possible causes - Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit fuse
- Faulty Engine Control Module (ECM) When is the code detected? The P0037 is set when the ECM detects an excessively low voltage through the heated oxygen sensor heater circuit P0037 LEXUS Description Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module (ECM).

In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECMcontrols the heater element circuit by allowing current flow to ground.

The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.

Grand Cherokee oxygen sensor locations for 4.0 and 4.7 engines...






An O2 sensor is a galvanic battery that provides the PCM with a voltage signal (0-1 volt) inversely proportional to the amount of oxygen in the exhaust. In other words, if the oxygen content is low, the voltage output is high; if the oxygen content is high the output voltage is low. The PCM uses this information to adjust injector pulse-width to achieve the 14.7-to-1 air/fuel ratio necessary for proper engine operation and to control emissions.

The O2 sensor must have a source of oxygen from outside of the exhaust stream for comparison. Current O2 sensors receive their fresh oxygen (outside air) supply through the O2 sensor case housing.

Four wires (circuits) are used on each O2 sensor:
* 12-volt feed circuit for the sensor heating element
* Ground circuit for the heater element
* Low-noise sensor return circuit to the PCM
* Input circuit from the sensor back to the PCM to detect sensor operation


Hope helps (remember to rate and commene this)..

from the autozone.com web site. click on red X's to view pictures.

OPERATION


See Figure 1
The heated oxygen sensor, or HO2S sensor is located at the exhaust system, usually near the catalytic converter. It produces a voltage signal of 0.1-1.0 volts based on the amount of oxygen in the exhaust gas. When a low amount of oxygen is present (caused by a rich air/fuel mixture), the sensor produces a low voltage. When a high amount of oxygen is present (caused by a lean air/fuel mixture), the sensor produces a high voltage. Because an accurate voltage signal is only produced if the sensor temperature is above approximately 600°F, a fast acting heating element is built into its body.
The ECU uses the HO2S sensor voltage signal to constantly adjust the amount of fuel injected which keeps the engine at its peek efficiency.

Fig. Fig. 1: Common oxygen sensor used on the 1989-90 MPI system

TESTING

1. Start the engine and bring it to normal operating temperature, then run the engine above 1200 rpm for two minutes.
2. Backprobe with a high impedance averaging voltmeter (set to the DC voltage scale) between the HO2S sensor signal wire and battery ground.
3. Verify that the sensor voltage fluctuates rapidly between 0.40-0.60 volts.
4. If the sensor voltage is stabilized at the middle of the specified range (approximately 0.45-0.55 volts) or if the voltage fluctuates very slowly between the specified range (H02S signal crosses 0.5 volts less than 5 times in ten seconds), the sensor may be faulty.
5. If the sensor voltage stabilizes at either end of the specified range, the ECU is probably not able to compensate for a mechanical problem such as a vacuum leak. These types of mechanical problems will cause the sensor to report a constant lean or constant rich mixture. The mechanical problem will first have to be repaired and then the H02S sensor test repeated.
6. Pull a vacuum hose located after the throttle plate. Voltage should drop to approximately 0.12 volts (while still fluctuating rapidly). This tests the ability of the sensor to detect a lean mixture condition. Reattach the vacuum hose.
7. Richen the mixture using a propane enrichment tool. Sensor voltage should rise to approximately 0.90 volts (while still fluctuating rapidly). This tests the ability of the sensor to detect a rich mixture condition.
8. If the sensor voltage is above or below the specified range, the sensor and/or the sensor wiring may be faulty. Check the wiring for any breaks, repair as necessary and repeat the test.
9. Further sensor operational testing requires the use of a special tester M.S.1700, or equivalent.

Removal & Installation

1. Raise the vehicle and support it with jackstands.
2. Disengage the HO2S sensor wiring connector and remove it using tool YA 8875, or its equivalent.

To install:

1. Inspect the threads of the HO2S sensor. Apply an anti-seize compound only if there is none visible on the threads. Be careful not to contaminate the sensor tip with any foreign compounds.
2. Install the sensor using tool YA 8875, or its equivalent and engage the wiring connector.
3. Carefully lower the vehicle.

P0146:
O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)
The PCM provides a 0.45 volt reference to the oxygen sensor on CKT 1668. When the Oxygen Sensor reaches operating temperature it will generate a counter voltage that will vary based on the amount of oxygen in the exhaust. The post-converter heated oxygen sensor is located in the exhaust after the catalytic converter. A lean exhaust will generate a low voltage and cause the 0.45 reference to move lower. A rich exhaust will generate a high voltage and cause the 0.45 reference to move higher. If the oxygen sensor cannot respond under the test conditions and generate a voltage greater than 0.609 volt or less than 0.307 volt, it will set a DTC P0146. Possible causes of DTC P0146 are:

• Open in CKT 1668 or 1669.
• Short to voltage on CKT 1668 or 1669.
• Oxygen sensor that malfunctions.
• An ineffective oxygen sensor heater.
• A poor HO2S ground.

P0147 :O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 3)
This diagnostic test is used to determine if the heating element in the post-converter oxygen sensor is operating properly. An oxygen sensor acts as a battery because it creates its own voltage once it reaches operating temperature. This voltage is produced when the oxygen content in the exhaust stream is different than that in the atmosphere. The heating element is energized through CKT 139 when the ignition is ON and allows the oxygen sensor to reach operating temperature quickly. This in turn allows the PCM to enter Closed Loop fuel control quicker. When cold the voltage that the PCM measures on the HO2S HI and LOW inputs is called bias voltage. If it takes too long for the HO2S to vary above or below the bias voltage within a specific time since key ON DTC P0147 will set

P1323:IC 24X Referance Circut Low Frequency
The Ignition Control Module creates a 4X signal and a 24X signal that is used by the PCM for ignition and fuel control. In this diagnostic test, the PCM checks for 4X reference pulses being received without 24X reference pulses. When the engine is running and the PCM is receiving 4X reference pulses without 24X reference pulses and the 24X reference signal line is low for 4 seconds, DTC P1323 is set.

P01377:IC Cam Pulse To 4X Referance
This diagnostic test checks to see if there are eight 4X reference pulses between CAM signals. Do not attempt diagnosis or repair unless the customer is experiencing driveability problems associated with this DTC.

Hope this helps!

Hello mrsalbert, my name is JShreader. Thank you for choosing fixya.com

Depending on which oxygen sensor you are looking for...there are several of them throughout the Exhaust System. I will start out by giving you a brief description of what and oxygen sensor is, and they're general purpose.

DESCRIPTION
Four Heated Oxygen Sensors (HO2S) are mounted in the exhaust system where they monitor the oxygen content in the exhaust stream. There is an oxygen sensor mounted in each exhaust manifold and one on each end of the catalytic converter. the oxygen sensor located in the front exhaust manifold is the Bank 2 Sensor 1 (Front) sensor. The oxygen sensor located in the rear exhaust manifold is the Bank 1 Sensor 1 (Rear) sensor. The oxygen sensor located in the Y-pipe ahead of the catalytic converter is the Bank 1 Sensor 2 (Pre-converter) sensor. The oxygen sensor located in the catalytic converter outlet is the Bank 1 Sensor 3 (Post-converter) sensor.

OPERATION
An oxygen sensor acts like a battery because it creates its own signal voltage once it reaches operating temperature. This voltage is produced when the oxygen content in the exhaust stream is different than the oxygen content in the atmosphere. A lean condition (high oxygen content in exhaust) will produce a low voltage (near 0 volts) and a rich condition (low oxygen content in exhaust) will produce a high voltage (near one volt). The PCM provides a reference signal voltage (0.45 volt) and a ground to the sensor. The PCM reference voltage is necessary because the oxygen sensors do not provide their own voltage until they reach operating temperature.

HEATING ELEMENT
the oxygen sensors also incorporate a heating element inside of the sensor housing. This heating element is energized with the ignition On and allows the sensors to reach operating temperatures quickly. The PCM can then use oxygen sensor information sooner after engine start-up.

PCM INPUTS
The PCM uses oxygen sensor information during Closed Loop operation to constantly adjust fuel control to reduce exhaust emissions. Because the oxygen sensors provide information sooner after engine start-up, exhaust emissions are reduced. Faulty oxygen sensors will cause various driveability conditions and will set a DTC.

That being said...I uploaded a .pdf for you of pictures showing the locations of ALL the oxygen Sensors on your Vehicle. You can download it by clicking HERE.

I hope this helps you. If you have any more questions or need any more diagrams, please don't hesitate to ask...Thanks again, JShreader!