P0037

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0037, P0038, P0057, P0058, P0141, P0161, P102D, P105D: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
P105D - O2 Sensor Heater Circuit Performance Bank 2 Sensor 2 Stuck ON

DESCRIPTION

Refer to DTC P0136 P0136.

HINT
- When any of these DTCs are set, the ECM enters fail-safe mode. The ECM turns off the Heated Oxygen (HO2) sensor heater in fail-safe mode. Fail-safe mode continues until the engine switch is turned off.
- The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The HO2 sensor heater circuit uses a relay on the +B side of the circuit.









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.

Heated Oxygen Sensor Heater Range Check (P0037, P0038, P0057, P0058, P102D and P105D):

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.

Heated Oxygen Sensor Heater Performance (P0141 and P0161):

After the accumulated heater on time exceeds 100 seconds, the ECM calculates the heater resistance using battery voltage and the current applied to the heater. If the resistance is above the threshold value, the ECM determines that there is a malfunction in the heated oxygen sensor heater and stores DTC P0141 and P0161.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





P0037 and P0057 (Case 1)





P0037 and P0057 (Case 2)





P0038 and P0058





P0141 and P0161





P102D and P105D





TYPICAL MALFUNCTION THRESHOLDS

P0037 and P0057 (Case 1)





P0037 and P0057 (Case 2)





P0038 and P0058





P0141 and P0161





P102D and P105D





MONITOR RESULT

- Refer to CHECKING MONITOR STATUS Mode 6 Data.

CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Start the engine and idle it for 5 minutes or more [B].

7. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 3000 rpm for 1 minute [C].

8. Idle the engine for 5 minutes or more [D].

9. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

10. Read the pending DTC [E].

11. If a pending DTC is output, the system is malfunctioning.

HINT
If a pending DTC is not output, perform the following procedure.

12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

13. Input the DTC: P0037, P0038, P0057, P0058, P0141, P0161, P102D or P105D.

14. Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or N/A, perform step [B] through [D] again.

15. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

16. Check the judgment result.

HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.

17. If the test result is INCOMPLETE or N/A and no pending 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

Refer to DTC P0136 P0136.

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
- Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transaxle.
- Bank 2 refers to the bank that does not include the No. 1 cylinder.
- Sensor 1 refers to the sensor closest to the engine assembly.
- Sensor 2 refers to the sensor farthest away from the engine assembly.
- 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 P0136. If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
- 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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction Freeze Frame Data.

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. CHECK TERMINAL VOLTAGE (+B OF HO2 SENSOR)

(a) Disconnect the B24 heated oxygen sensor connector (Bank 1 Sensor 2) or B25 heated oxygen sensor connector (Bank 2 Sensor 2).





(b) Turn the engine switch on (IG).

(c) Measure the voltage between the terminals.

Standard voltage:





(d) Reconnect the HO2 sensor connector.

OK -- CHECK HARNESS AND CONNECTOR (HO2 SENSOR - ECM)
NG -- Continue to next step.

3. INSPECT ENGINE ROOM JUNCTION BLOCK

(a) Inspect the EFI relay Testing and Inspection.

NG -- REPLACE ENGINE ROOM JUNCTION BLOCK
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (HO2 SENSOR - EFI RELAY)

(a) Disconnect the B24 or B25 heated oxygen sensor connector.

(b) Remove the engine room junction block from the engine room R/B.

(c) Measure the resistance between the terminals.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reinstall the engine room junction block.

(e) Reconnect the HO2 sensor connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit

5. CHECK HARNESS AND CONNECTOR (HO2 SENSOR - ECM)

(a) Disconnect the B24 heated oxygen sensor connector (Bank 1 Sensor 2) or B25 heated oxygen sensor connector (Bank 2 Sensor 2).

(b) Disconnect the B12 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):





(d) Reconnect the HO2 sensor connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. CHECK WHETHER DTC OUTPUT RECURS

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(f) Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

(g) Read the pending DTCs.

Result:





B -- REPLACE ECM Removal

A -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems