P0037
FA20 ENGINE CONTROL: SFI SYSTEM: P0037, P0038, P0141; Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2); 2013 MY FR-S [03/2012 -]
P0037 - Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
P0038 - Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)
P0141 - Oxygen Sensor Heater Circuit (Bank 1 Sensor 2)
DESCRIPTION
Refer to DTC P0137 P0137.
MONITOR DESCRIPTION
The sensing portion of the heated oxygen sensor has a zirconia element which is used to detect the oxygen concentration in the exhaust gas. If the zirconia element is at the appropriate temperature, and the difference between the oxygen concentrations surrounding the inside and outside surfaces of the sensor is large, the zirconia element generates voltage signals. In order to increase the oxygen concentration detecting capacity of the zirconia element, the ECM supplements the heat from the exhaust with heat from a heating element inside the sensor.
The ECM monitors the current applied to the heated oxygen sensor heater to check the heater for malfunctions.
If the heater current is outside the normal range, the signal transmitted by the heated oxygen sensor becomes inaccurate. When the current in the heated oxygen sensor heater is outside the normal operating range, the ECM interprets this as a malfunction in the sensor heater and stores a DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
P0037
P0038
P0141
TYPICAL MALFUNCTION THRESHOLDS
P0037
P0038
P0141
MONITOR RESULT
Refer to detailed information in Checking Monitor Status Mode 6 Data.
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation) Reading and Clearing Diagnostic Trouble Codes.
4. Turn the ignition switch off and wait for at least 30 seconds.
5. Turn the ignition switch to ON and turn the Techstream on.
6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
7. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of between 2500 and 3000 rpm for 40 seconds or more [A].
8. Drive the vehicle at 10 km/h (6.25 mph) or more for 1 minute or more [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
9. Enter the following menus: Powertrain / Engine / Trouble Codes.
10. Read pending DTCs.
HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.
11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
12. Input the DTC: P0037, P0038 or P0141.
13. Check the DTC judgment result.
HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
14. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
* Sensor 1 refers to the sensor closest to the engine assembly.
* Sensor 2 refers to the sensor farthest away from the engine assembly.
* Refer to "Data List / Active Test" [O2 Heater B1S2 and O2 Heater Curr Val B1S2] Data List / Active Test.
* When the values for the Data List item O2 Heater Curr Val B1S2 is not 0 A, the heater is on.
* Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
* Change the fuel injection volume using the Control the Injection Volume function provided in the Active Test and monitor the heated oxygen sensor output voltage P0137. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
PROCEDURE
1. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
(a) Inspect the heated oxygen sensor Heated Oxygen Sensor.
NG -- REPLACE HEATED OXYGEN SENSOR Removal
OK -- Continue to next step.
2. INSPECT TERMINAL VOLTAGE (POWER SOURCE OF HEATED OXYGEN SENSOR)
(a) Disconnect the heated oxygen sensor connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
NG -- INSPECT RELAY (EFI MAIN2)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)
(a) Disconnect the heated oxygen sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open):
Standard Resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0037 OR P0038)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON.
(g) Turn the Techstream on.
(h) Start the engine.
(i) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(j) Enter the following menus: Powertrain / Engine / Trouble Codes.
(k) Read pending DTCs.
Result
B -- REPLACE ECM Removal
A -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
5. INSPECT RELAY (EFI MAIN2)
(a) Check the EFI MAIN2 relay Testing and Inspection.
NG -- REPLACE RELAY (EFI MAIN2)
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - EFI MAIN2 RELAY)
(a) Disconnect the heated oxygen sensor connector.
(b) Remove the EFI MAIN2 relay from the engine room relay block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open):
Standard Resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit