2012 Toyota Truck Tundra 2WD V8-4.6L (1UR-FE)
Vehicle > ALL Diagnostic Trouble Codes ( DTC ) > Testing and Inspection > P Code Charts > P0141
SFI SYSTEM
1UR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0037, P0038, P0057, P0058, P0141, P0161, P102D, P105D: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
DESCRIPTION
- Refer to DTC P0136 See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts > SFI System.
HINT
* When any of these DTCs are stored, 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 ignition 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 (HO2) 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 HO2 sensor heater to check the heater for malfunctions.
If the heater current is outside the normal range, the signal transmitted by the HO2 sensor becomes inaccurate. When the current in the HO2 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 the 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 HO2 sensor heater and stores DTC P0141 or P0161.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS P0037 and P0057 (Case 1)
P0037 and P0057 (Case 2)
P0038 and P0058
P0141 and P0161 (Case 1)
P0141 and P0161 (Case 2)
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
COMPONENT OPERATING RANGE
MONITOR RESULT
Refer to Checking Monitor Status See: Computers and Control Systems > Mode 6 Data > Checking Monitor Status.
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).
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 [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 and ECT / Trouble Codes [E].
10. Read the 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 and ECT / Utility / All Readiness.
12. Input the DTC: P0037, P0038, P0057, P0058, P0141, P0161, P102D or P105D.
13. Check the DTC judgment result.
14. If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [E] again.
15. If no pending DTC is output, perform a universal trip and check for permanent DTCs See: Computers and Control Systems >
Reading and Clearing Diagnostic Trouble Codes > DTC Check / Clear.
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 See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts > SFI System.
INSPECTION PROCEDURE
HINT
* Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. 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.
* Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
* 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.
PROCEDURE
1. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
(a)Disconnect the HO2 sensor connector.
(b)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE HEATED OXYGEN SENSORSee: Oxygen Sensor > Removal and Replacement > Removal OK -- Continue to next step.
2. CHECK TERMINAL VOLTAGE (+B OF HO2 SENSOR)
(a)Disconnect the HO2 sensor connector.
(b)Turn the ignition switch to ON.
(c)Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Result
B -- CHECK HARNESS AND CONNECTOR (HO2 SENSOR - ECM) A -- Continue to next step.
3. INSPECT INTEGRATION RELAY (EFI)
(a)Remove the integration relay from the engine room relay block.
(b)Inspect the EFI NO. 1 fuse.
(1)Remove the EFI NO. 1 fuse from the integration relay.
(2)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(3)Reinstall the EFI NO. 1 fuse.
(c)Inspect the EFI relay.
(1)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE INTEGRATION RELAY (EFI) OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (HO2 SENSOR - INTEGRATION RELAY) (a)Check the EFI NO. 2 fuse.
(1)Remove the EFI NO. 2 fuse from the engine room relay block.
(2)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(3)Reinstall the EFI NO. 2 fuse.
(b)Disconnect the HO2 sensor connector.
(c)Remove the integration relay from the engine room relay block.
(d)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- CHECK ECM POWER SOURCE CIRCUITSee: Computers and Control Systems > Component Tests and General Diagnostics > ECM Power Source Circuit
5. CHECK HARNESS AND CONNECTOR (HO2 SENSOR - ECM)
(a)Disconnect the HO2 sensor connector.
(b)Disconnect the ECM connector.
(c)Measure the resistance according to the value(s) in the table below.
Standard Resistance:
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 ignition switch to ON.
(c)Turn the Techstream on.
(d)Clear DTCs See: Computers and Control Systems > Reading and Clearing Diagnostic Trouble Codes > DTC Check / Clear.
(e)Start the engine.
(f)Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(g)Read the output pending DTCs using the Techstream.
Result
B -- REPLACE ECMSee: Engine Control Module > Removal and Replacement > Removal
A -- CHECK FOR INTERMITTENT PROBLEMSSee: Computers and Control Systems > Initial Inspection and Diagnostic Overview > Check for Intermittent Problems
