CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS
DTC P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (for A/F sensor) (Bank 1 Sensor 1) |
DTC P2238 Oxygen Sensor Pumping Current Circuit Low (for A/F sensor) (Bank 1 Sensor 1) |
DTC P2239 Oxygen Sensor Pumping Current Circuit High (for A/F sensor) (Bank 1 Sensor 1) |
DTC P2240 Oxygen (A/F) Sensor Pumping Current Circuit / Open (for A/F sensor) (Bank 2 Sensor 1) |
DTC P2241 Oxygen Sensor Pumping Current Circuit Low (for A/F sensor) (Bank 2 Sensor 1) |
DTC P2242 Oxygen Sensor Pumping Current Circuit High (for A/F sensor) (Bank 2 Sensor 1) |
DTC P2252 Oxygen Sensor Reference Ground Circuit Low (for A/F sensor) (Bank 1 Sensor 1) |
DTC P2253 Oxygen Sensor Reference Ground Circuit High (for A/F sensor) (Bank 1 Sensor 1) |
DTC P2255 Oxygen Sensor Reference Ground Circuit Low (for A/F sensor) (Bank 2 Sensor 1) |
DTC P2256 Oxygen Sensor Reference Ground Circuit High (for A/F sensor) (Bank 2 Sensor 1) |
DESCRIPTION
- HINT:
- Although the DTC titles say heated oxygen sensor, these DTCs relate to the air fuel ratio sensor.
- Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.
Depending on the engine operating conditions, the heater heats the sensor elements to activate them. Battery voltage is applied to the heater and the sensor ground is controlled by the ECM using a duty ratio.
The sensor elements convert the oxygen concentration in the exhaust gas into voltage values to output. Based on the voltage, the ECM determines the air fuel ratio and regulates the fuel injection volume according on the air fuel ratio and engine operating conditions. The voltage changes between 0.5 V and 4.5 V while the engine is running. If the air fuel ratio is lean, which means the oxygen concentration in the exhaust gas is high, the voltage is high. If the air fuel ratio is rich, which means the oxygen concentration in the exhaust gas is low, the voltage is low.
| DTC No. | DTC Detection Condition | Trouble Area |
| P2237 P2240 | An open in the circuit between terminals A1A+/A2A+ and A1A-/A2A- of the air fuel ratio sensor while the engine is running (2 trip detection logic). |
|
| P2238 P2241 | Any of the following conditions are met (2 trip detection logic):
|
|
| P2239 P2242 | The A1A+/A2A+ voltage is higher than 4.5 V (2 trip detection logic). |
|
| P2252 P2255 | The A1A-/A2A- voltage is 0.5 V or less (2 trip detection logic). |
|
| P2253 P2256 | The A1A-/A2A- voltage is higher than 4.5 V (2 trip detection logic). |
|
MONITOR DESCRIPTION
These DTCs are stored when there is an open or short in the air fuel ratio sensor circuit, or if the air fuel ratio sensor output drops. To detect these problems, the voltage of the air fuel ratio sensor is monitored when turning the engine switch on (IG), and the admittance (admittance is an electrical term that indicates the ease of current flow) is checked while driving. If the voltage of the air fuel ratio sensor is between 0.5 V and 4.5 V, it is considered normal. If the voltage is out of the specified range, or the admittance is less than the standard value, the ECM will determine that there is a malfunction in the air fuel ratio sensor. If the same malfunction is detected in the next driving cycle, the MIL will be illuminated and a DTC will be stored.WIRING DIAGRAM
Refer to DTC P2195 (LandCruiser RM000000WC40YDX_07.html).CONFIRMATION DRIVING PATTERN
- HINT:
- This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" step of the following diagnostic troubleshooting procedure.
- Performing this confirmation driving pattern will activate the heated oxygen sensor monitor. This is useful for verifying the completion of the repair.
- Connect the GTS to the DLC3.
- Turn the engine switch on (IG).
- Turn the GTS on.
- Clear the DTCs (LandCruiser RM000000PDK1DIX.html).
- Switch the ECM from normal mode to check mode (LandCruiser RM000000PDL0Y3X.html).
- Enter the following menus: Powertrain / Engine and ECT / Data List / O2S (A/FS) Monitor.
- Check that the item O2S (A/FS) Monitor displays Incmpl (incomplete).
- Start the engine and warm it up. (A)
- Drive the vehicle at between 60 km/h and 120 km/h (37 mph and 75 mph) for at least 10 minutes. (B)
- Note the state of the Data List items. Those items will change to Compl (complete) as the heated oxygen sensor monitor operates.
- On the GTS, enter the following menus: Powertrain / Engine and ECT / Trouble Codes; and check if any DTCs (any pending DTCs) are output.
- HINT:
- If the item O2S (A/FS) Monitor does not change to Compl (complete) and any pending DTCs fail to be stored, extend the driving time.
INSPECTION PROCEDURE
- HINT:
- Malfunctioning areas can be identified by performing the Control the Injection Volume for air fuel ratio sensor function provided in the Active Test. The Control the Injection Volume for air fuel ratio sensor function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.
- The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the GTS.
- Connect the GTS to the DLC3.
- Start the engine and turn the GTS on.
- Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
- On the GTS, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
- Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
- Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the GTS.
- HINT:
- The Control the Injection Volume for air fuel ratio sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
| GTS Display (Sensor) | Injection Volume | Status | Voltage |
| AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio sensor) | +12.5% | Rich | Below 3.1 V |
| AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio sensor) | -12.5% | Lean | Higher than 3.4 V |
| O2S B1S2 or O2S B2S2 (Heated oxygen sensor) | +12.5% | Rich | Higher than 0.55 V |
| O2S B1S2 or O2S B2S2 (Heated oxygen sensor) | -12.5% | Lean | Below 0.4 V |
- NOTICE:
- The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
| Case | Air Fuel Ratio Sensor (Sensor 1) Output Voltage | Heated Oxygen Sensor (Sensor 2) Output Voltage | Main Suspected Trouble Area |
| 1 |   |  | - |
| 2 |  | |
|
| 3 | | |
|
| 4 | | |
|
- Following the Control the Injection Volume for air fuel ratio sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.
- To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.
- HINT:
- Read freeze frame data using the GTS. 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.
| 1.CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) |
Disconnect the air fuel ratio sensor connector.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Switch Condition Specified Condition C25-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V C26-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V
Turn the engine switch off.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
for Automatic Transmission Tester Connection Condition Specified Condition C25-1 (HA1A) - C37-17 (HA1A) Always Below 1 Ω C25-3 (A1A+) - C35-7 (A1A+) Always Below 1 Ω C25-4 (A1A-) - C35-8 (A1A-) Always Below 1 Ω C26-1 (HA2A) - C37-12 (HA2A) Always Below 1 Ω C26-3 (A2A+) - C35-1 (A2A+) Always Below 1 Ω C26-4 (A2A-) - C35-2 (A2A-) Always Below 1 Ω for Manual Transmission Tester Connection Condition Specified Condition C25-1 (HA1A) - C37-17 (HA1A) Always Below 1 Ω C25-3 (A1A+) - C36-1 (A1A+) Always Below 1 Ω C25-4 (A1A-) - C36-2 (A1A-) Always Below 1 Ω C26-1 (HA2A) - C37-19 (HA2A) Always Below 1 Ω C26-3 (A2A+) - C36-7 (A2A+) Always Below 1 Ω C26-4 (A2A-) - C36-8 (A2A-) Always Below 1 Ω
- Standard Resistance (Check for Short):
for Automatic Transmission Tester Connection Condition Specified Condition C25-1 (HA1A) or C37-17 (HA1A) - Body ground Always 10 kΩ or higher C25-3 (A1A+) or C35-7 (A1A+) - Body ground Always 10 kΩ or higher C25-4 (A1A-) or C35-8 (A1A-) - Body ground Always 10 kΩ or higher C26-1 (HA2A) or C37-12 (HA2A) - Body ground Always 10 kΩ or higher C26-3 (A2A+) or C35-1 (A2A+) - Body ground Always 10 kΩ or higher C26-4 (A2A-) or C35-2 (A2A-) - Body ground Always 10 kΩ or higher for Manual Transmission Tester Connection Condition Specified Condition C25-1 (HA1A) or C37-17 (HA1A) - Body ground Always 10 kΩ or higher C25-3 (A1A+) or C36-1 (A1A+) - Body ground Always 10 kΩ or higher C25-4 (A1A-) or C36-2 (A1A-) - Body ground Always 10 kΩ or higher C26-1 (HA2A) or C37-19 (HA2A) - Body ground Always 10 kΩ or higher C26-3 (A2A+) or C36-7 (A2A+) - Body ground Always 10 kΩ or higher C26-4 (A2A-) or C36-8 (A2A-) - Body ground Always 10 kΩ or higher
Reconnect the air fuel ratio sensor connector.
Reconnect the ECM connector.
|
| ||||
| OK | |
| 2.REPLACE AIR FUEL RATIO SENSOR |
Replace the air fuel ratio sensor (LandCruiser RM000002W9Q017X.html).
- HINT:
- for Automatic Transmission
- Perform "Inspection After Repair" after replacing the air fuel ratio sensor (LandCruiser RM000004NJC03SX.html).
| NEXT | |
| 3.PERFORM CONFIRMATION DRIVING PATTERN |
| NEXT | |
| 4.CHECK WHETHER DTC OUTPUT RECURS |
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs (LandCruiser RM000000PDK1DIX.html).
Start the engine.
Allow the engine to idle for 5 minutes or more.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Read the pending DTCs.
Result Result Proceed to No output A P2237, P2240, P2238, P2241, P2239, P2242, P2252, P2255, P2253 or P2256 output B
|
| ||||
| A | ||
| ||