- Open or short in Heated Oxygen (HO2) sensor (bank 1, 2 sensor 2) circuit
- Heated Oxygen (HO2) sensor (bank 1, 2 sensor 2)
- Heated Oxygen (HO2) sensor heater (bank 1, 2 sensor 2)
- Air Fuel Ratio (A/F) sensor (bank 1, 2 sensor 1)
- EFI relay
- Gas leakage from exhaust system
| Last Modified: 4-30-2014 | 6.6 C | Doc ID: RM000000WBY00EX |
| Model Year: 2006 | Model: LX470 | Prod Date Range: [05/2005 - ] |
| Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0136-P0138,P0156-P0158; Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2); 2006 MY LX470 [05/2005 - ] | ||
|
DTC |
P0136 |
Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2) |
|
DTC |
P0137 |
Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2) |
|
DTC |
P0138 |
Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2) |
|
DTC |
P0156 |
Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 2) |
|
DTC |
P0157 |
Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 2) |
|
DTC |
P0158 |
Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2) |
DESCRIPTION
HINT:
Sensor 2 refers to the sensor mounted behind the Three-Way Catalyst Converter (TWC) and located far from the engine assembly.
In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric air fuel level. For the purpose of helping the ECM to deliver accurate air fuel ratio control, a Heated Oxygen (HO2) sensor is used.
The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air fuel ratio becomes lean, the oxygen concentration in the exhaust gas is rich. The HO2 sensor informs the ECM that the post-TWC air fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air fuel ratio is richer than the stoichiometric air fuel level, the oxygen concentration in the exhaust gas becomes lean. The HO2 sensor has the property of changing its output voltage drastically when the air fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the HO2 sensor to determine whether the air fuel ratio after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air fuel ratio control.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P0136 P0156 |
During active air fuel ratio control, following conditions (a) and (b) are met for certain period of time (2 trip detection logic): (a) Heated Oxygen (HO2) sensor voltage does not decrease to less than 0.2 V (b) HO2 sensor voltage does not increase to more than 0.6 V |
|
|
P0136 P0156 |
Sensor impedance less than 5 Ω for more than 30 seconds when ECM presumes sensor to being warmed up and operating normally (1 trip detection logic) |
|
|
P0137 P0157 |
During active air fuel ratio control, following conditions (a) and (b) are met for certain period of time (2 trip detection logic): (a) HO2 sensor voltage output less than 0.21 V (b) Target air fuel ratio rich |
|
|
P0137 P0157 |
High impedance: Sensor impedance 15 kΩ or more for more than 90 seconds when ECM presumes sensor to being warmed up and operating normally (1 trip detection logic) |
|
|
P0138 P0158 |
During active air fuel ratio control, following conditions (a) and (b) are met for certain period of time (2 trip detection logic): (a) HO2 sensor voltage output 0.59 V or more (b) Target air fuel ratio lean |
|
|
P0138 P0158 |
HO2 sensor voltage output exceeds 1.2 V for more than 30 seconds (1 trip detection logic) |
MONITOR DESCRIPTION
-
Active Air Fuel ratio Control
The ECM usually performs air fuel ratio feedback control so that the Air Fuel Ratio (A/F) sensor output indicates a near stoichiometric air fuel level. This vehicle includes active air fuel ratio control in addition to regular air fuel ratio control. The ECM performs active air fuel ratio control to detect any deterioration in the Three-Way Catalytic Converter (TWC) and Heated Oxygen (HO2) sensor malfunctions (refer to the diagram below).
Active air fuel ratio control is performed for approximately 15 to 20 seconds while driving with a warm engine.
During active air fuel ratio control, the air fuel ratio is forcibly regulated to become lean or rich by the ECM.
If the ECM detects a malfunction, one of the following DTCs is set: DTC P0136, P0156 (abnormal voltage output), P0137, P0157 (open circuit) and P0138, P0158 (short circuit).
-
Abnormal Voltage Output of HO2 Sensor (DTC P0136 and P0156)
While the ECM is performing active air fuel ratio control, the air fuel ratio is forcibly regulated to become rich or lean. If the sensor is not functioning properly, the voltage output variation is small. For example, when the HO2 sensor voltage does nor decrease to less than 0.21 V and does not increase to more than 0.59 V during active air fuel ratio control, the ECM determines that the sensor voltage output is abnormal and sets DTC P0136 and P0156.
-
Open or short in the Heated Oxygen (HO2) Sensor Circuit (DTC P0137, P0157, P0138 or P0158)
During active air fuel ratio control, the ECM calculates the Oxygen Storage Capacity (OSC)* of the Three-Way Catalytic Converter (TWC) by forcibly regulating the air fuel ratio to become rich or lean.
If the HO2 sensor has an open or short, or the voltage output of the sensor noticeably decreases, the OSC indicates an extraordinarily high value. Even if the ECM attempts to continue regulating the air fuel ratio to become rich or lean, the HO2 sensor output does not change.
While performing active air fuel ratio control, when the target air fuel ratio is rich and the HO2 sensor voltage output is 0.21 V or less (lean), the ECM interprets this as an abnormally low sensor output voltage and sets DTC P0137 or P0157. When the target air fuel ratio is lean and the voltage output is 0.59 V or more (rich) during active air fuel ratio control, the ECM determines that the sensor voltage output is abnormally high, and sets DTC P0138 or P0158.
HINT:
DTC P0138 or P0158 is also set if the HO2 sensor voltage output is more than 1.2 V for 30 seconds or more.
*: The TWC has the capability to store oxygen. The OSC and the emission purification capacity of the TWC are mutually related. The ECM determines whether the catalyst has deteriorated, based on the calculated OSC value
![2006 MY LX470 [05/2005 - ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0420,P0430; Catalyst System Efficiency Below Threshold (Bank 1)](../../../../stylegraphics/info.gif "2006 MY LX470 [05/2005 - ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0420,P0430; Catalyst System Efficiency Below Threshold (Bank 1)")
.
-
High or Low Impedance of Heated Oxygen (HO2) Sensor (DTC P0136, P0156, P0137 or P0157)
During normal air fuel ratio feedback control, there are small variations in the exhaust gas oxygen concentration. In order to continuously monitor the slight variation of the HO2 sensor signal while the engine is running, the impedance* of the sensor is measured by the ECM. The ECM determines that there is a malfunction in the sensor when the measured impedance deviates from the standard range.
HINT:
- *: The effective resistance in an alternating current electrical circuit.
- The impedance cannot be measured using an ohmmeter.
- DTC P0136 or P0156 indicates the deterioration of the HO2 sensor. The ECM sets the DTC by calculating the impedance of the sensor when the typical enabling conditions are satisfied (1 driving cycle).
- DTC P0137 or P0157 indicates an open circuit in the HO2 sensor (1 driving cycle). The ECM sets this DTC when the impedance of the sensor exceeds the threshold 348.1 MΩ.
MONITOR STRATEGY
|
Related DTCs |
P0136: Heated oxygen sensor (Bank 1) output voltage (Output voltage) P0136: Heated oxygen sensor (Bank 1) impedance (Low) P0137: Heated oxygen sensor (Bank 1) output voltage (Low voltage) P0137: Heated oxygen sensor (Bank 1) impedance (High) P0138: Heated oxygen sensor (Bank 1) output voltage (High voltage) P0138: Heated oxygen sensor (Bank 1) output voltage (Extremely high) P0156: Heated oxygen sensor (Bank 2) output voltage (Output voltage) P0156: Heated oxygen sensor (Bank 2) impedance (Low) P0157: Heated oxygen sensor (Bank 2) output voltage (Low voltage) P0157: Heated oxygen sensor (Bank 2) impedance (High) P0158: Heated oxygen sensor (Bank 2) output voltage (High voltage) P0158: Heated oxygen sensor (Bank 2) output voltage (Extremely high) |
|
Required Sensors/Components (Main) |
Heated oxygen sensor |
|
Required Sensors/Components (Related) |
Mass air flow meter |
|
Frequency of Operation |
Unified cycle |
|
Duration |
20 seconds: Heated oxygen sensor output (Output voltage, High voltage, Low voltage) 30 seconds: Heated oxygen sensor impedance (Low) 90 seconds: Heated oxygen sensor impedance (High) 10 seconds: Heated oxygen sensor impedance (Extremely high) |
|
MIL Operation |
2 driving cycles |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
All:
|
The monitor will run whenever these DTCs are not present |
P0031, P0032, P0051, P0052 (A/F sensor heater - Sensor 1) P0037, P0038, P0057, P0058 (O2 sensor heater - Sensor 2) P0100 - P0103 (MAF meter) P0110 - P0113 (IAT sensor) P0115 - P0118 (ECT sensor) P0120 - P0223, P2135 (TP sensor) P0125 (Insufficient ECT for closed loop) P0171, P0172 (Fuel system) P0300 - P0308 (Misfire) P0335 (CKP sensor) P0340, P0341 (CMP sensor) P0442 - P0456 (EVAP system) P0500 (VSS) P2196, P2198 (A/F sensor - rationality) P2440 (A/R control valve stuck open) P2441 (A/R control valve stuck close) P2444 (AIP stuck ON) P2445 (AIP stuck OFF) P2A00, P2A03 (A/F sensor - slow response) |
Heated oxygen sensor output voltage (Output voltage, High voltage, Low voltage):
|
Active air-fuel ratio control |
Executing |
|
Active air-fuel ratio control being when all of following conditions are met: |
- |
|
Battery voltage |
11 V or more |
|
Engine coolant temperature |
75°C (167°F) or more |
|
Idle |
OFF |
|
Engine RPM |
Less than 3,200 rpm |
|
Fuel system status |
Open loop and air pump is not operation |
|
A/F sensor status |
Activated |
|
Fuel-cut |
OFF |
|
Engine load |
10 to 70% |
|
Shift position |
4th or more |
Heated oxygen sensor impedance (Low):
|
Battery voltage |
11 V or higher |
|
Estimated sensor temperature |
Lower than 700°C (1,292°F) |
|
ECM monitor |
Completed |
|
P0606 |
Not set |
Heated oxygen sensor impedance (High):
|
Battery voltage |
11 V or more |
|
Estimated sensor temperature |
450°C (842°F) or more |
|
P0606 |
Not set |
Heated oxygen sensor output voltage (Extremely high):
|
Battery voltage |
11 V or more |
|
Time after engine start |
2 seconds or more |
TYPICAL MALFUNCTION THRESHOLDS
Heated oxygen sensor output voltage (Output voltage):
|
Either of the following conditions is met: |
Condition 1 or 2 |
|
1. All of the following conditions are met: |
Conditions (a), (b) and (c) |
|
(a) Commanded air-fuel ratio |
14.3 or less |
|
(b) Rear HO2S voltage |
0.21 to 0.59 V |
|
(c) OSC (Oxygen Storage Capacity of catalyst) |
3 g or more |
|
2. All of the following conditions are met: |
Conditions (a), (b) and (c) |
|
(a) Commanded air-fuel ratio |
14.9 or more |
|
(b) Rear HO2S voltage |
0.21 to 0.59 V |
|
(c) OSC (Oxygen Storage Capacity of catalyst) |
3 g or more |
Heated oxygen sensor output voltage (Low voltage):
|
All of the following conditions are met: |
Conditions 1, 2 and 3 |
|
1. Commanded air-fuel ratio |
14.3 or less |
|
2. Rear HO2S voltage |
Less than 0.21 V |
|
3. OSC (Oxygen Storage Capacity of catalyst) |
3 g or more |
Heated oxygen sensor output voltage (High voltage):
|
All of the following conditions are met: |
Conditions 1, 2 and 3 |
|
1. Commanded air-fuel ratio |
14.9 or more |
|
2. Rear HO2S voltage |
More than 0.59 V |
|
3. OSC (Oxygen Storage Capacity of catalyst) |
3 g or more |
Heated oxygen sensor impedance (Low):
|
Duration of the following condition |
30 seconds or more |
|
Heated oxygen sensor impedance |
Less than 5 Ω |
Heated oxygen sensor impedance (High):
|
Duration of the following condition |
90 seconds or more |
|
Heated oxygen sensor impedance |
15 kΩ or more |
Heated oxygen sensor impedance (Extremely high):
|
Duration of the following condition |
10 seconds or more |
|
Heated oxygen sensor impedance |
More than 1.2 V |
COMPONENT OPERATING RANGE
|
Heated Oxygen sensor voltage |
Varies between 0.1 and 0.9 V |
MONITOR RESULT
Detailed information on Checking Monitor Status
.
The test value and test limit information are in the following table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").
- Monitor Identification Date (MID) is assigned to each emissions-related component.
- Test Identification Date (TID) is assigned to each test value.
- Scaling is used to calculate the test value indicated on generic OBD II scan tools.
HO2S bank 1 sensor 2
|
MID |
TID |
Scaling |
Description of Test value |
Minimum Test Limit |
Maximum Test Limit |
|---|---|---|---|---|---|
|
$02 |
$07 |
Multiply by 0.001 [V] |
Minimum sensor voltage |
Minimum test limit |
Maximum test limit |
|
$02 |
$08 |
Multiply by 0.001 [V] |
Maximum sensor voltage |
Minimum test limit |
Maximum test limit |
|
$02 |
$8F |
Multiply by 0.001 [g] |
Maximum oxygen storage capacity |
0 |
Maximum test limit |
HO2S bank 2 sensor 2
|
MID |
TID |
Scaling |
Description of Test value |
Minimum Test Limit |
Maximum Test Limit |
|---|---|---|---|---|---|
|
$06 |
$07 |
Multiply by 0.001 [V] |
Minimum sensor voltage |
Minimum test limit |
Maximum test limit |
|
$06 |
$08 |
Multiply by 0.001 [V] |
Maximum sensor voltage |
Minimum test limit |
Maximum test limit |
|
$06 |
$8F |
Multiply by 0.001 [g] |
Maximum oxygen storage capacity |
0 |
Maximum test limit |
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
- (a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
- (b) Turn the ignition switch ON.
- (c) Turn the tester ON.
-
(d) Clear DTCs (if set)
.
- (e) Enter the following menus: DIAGNOSIS / CARB OBD ll / READINESS TESTS.
- (f) Check that O2S EVAL is INCMPL (incomplete).
- (g) Start the engine and warm it up.
- (h) Drive the vehicle at between 64 km/h and 113 km/h (40 mph and 70 mph) for at least 10 minutes.
- (i) Note the state of the Readiness Tests items. Those items will change to COMPL (complete) as O2S EVAL monitor operates.
- (j) Enter the following menus: DIAGNOSIS / ENHANCED OBD ll / DTC INFO / PENDING CODES and check if any pending DTCs are set.
HINT:
If O2S EVAL does not change to COMPL, and any pending DTCs fail to set, extend the driving time.
INSPECTION PROCEDURE
HINT:
Intelligent tester only:
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE TEST. The A/F CONTROL function can help to determine whether the Air Fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL operation using an intelligent tester.
- Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
- Start the engine and turn the tester ON.
- Warm up the engine at engine speed of 2,500 rpm for approximately 90 seconds.
- On the tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
- Perform the A/F CONTROL operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
- Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) displayed on the tester.
HINT:
- The A/F CONTROL operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases in the fuel injection volume.
Standard:
|
Tester Display (Sensor) |
Injection Volume |
Status |
Voltage |
|---|---|---|---|
|
AFS B1S1 or AFS B2S1 (A/F) |
+25% |
Rich |
Less than 3.0 |
|
AFS B1S1 or AFS B2S1 (A/F) |
-12.5% |
Lean |
More than 3.35 |
|
O2S B1S2 or O2S B2S2 (HO2) |
+25% |
Rich |
More than 0.55 |
|
O2S B1S2 or O2S B2S2 (HO2) |
-12.5% |
Lean |
Less than 0.4 |
NOTICE:
The Air Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.
|
Case |
A/F Sensor (Sensor 1) Output Voltage |
HO2 Sensor (Sensor 2) Output Voltage |
Main Suspected Trouble Area |
||
|---|---|---|---|---|---|
|
1 |
Injection Volume +25% -12.5% |
|
Injection Volume +25% -12.5% |
|
- |
|
Output Voltage More than 3.35 V Less than 3.0 V |
|
Output Voltage More than 0.55 V Less than 0.4 V |
|
||
|
2 |
Injection Volume +25% -12.5% |
|
Injection Volume +25% -12.5% |
|
|
|
Output Voltage Almost no reaction |
|
Output Voltage More than 0.55 V Less than 0.4 V |
|
||
|
3 |
Injection Volume +25% -12.5% |
|
Injection Volume +25% -12.5% |
|
|
|
Output Voltage More than 3.35 V Less than 3.0 V |
|
Output Voltage Almost no reaction |
|
||
|
4 |
Injection volume +25% -12.5% |
|
Injection Volume +25% -12.5% |
|
|
|
Output Voltage Almost no reaction |
|
Output Voltage Almost no reaction |
|
||
- Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
- To display the graph, enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2. Then press the YES button and ENTER button, followed by the F4 button.
HINT:
- If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.
- If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be set.
- If the OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0156 will be set.
PROCEDURE
|
1. |
CHECK OTHER DTC OUTPUT |
(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(d) Read DTCs.
Result:
|
Display (DTC Output) |
Proceed to |
|---|---|
|
P0138 or P0158 |
A |
|
P0137 or P0157 |
B |
|
P0136 or P0156 |
C |
| B |
|
| C |
|
|
|
2. |
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) |
(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
(b) After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
(c) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / O2S B1S2 or O2S B2S2.
(d) Allow the engine to idle.
(e) Read the Heated Oxygen (HO2) sensor output voltage while idling.
Result:
|
HO2 Sensor Output Voltage |
Proceed to |
|---|---|
|
More than 1.2 V |
A |
|
Less than 1.0 V |
B |
| B |
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT) |
|
(a) Turn the ignition switch OFF and wait for 5 minutes. (b) Disconnect the E7 and E8 ECM connectors. (c) Check the resistance. Standard resistance:
(d) Reconnect the ECM connector. |
|
| NG |
|
| OK |
|
|
4. |
INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT) |
|
(a) Disconnect the H8 or H17 Heated Oxygen (HO2) sensor connector. (b) Measure the resistance of the HO2 sensor connector. Standard resistance (Bank 1, 2 sensor 2):
(c) Reconnect the HO2sensor connector. |
|
| NG |
|
| OK |
|
|
5. |
PERFORM CONFIRMATION DRIVING PATTERN |
HINT:
Clear all DTCs prior to performing the confirmation driving pattern.
|
|
6. |
READ OUTPUT DTC (DTC P0138, P0158) |
(a) Enter the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
(b) Read DTCs.
Result:
|
Display (DTC output) |
Proceed to |
|---|---|
|
No output |
A |
|
P0136 and/or P0156 |
B |
| A |
|
| B |
|
|
7. |
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) |
(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Start the engine.
(d) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / O2S B1S2.
(e) After warming up the engine, run the engine at an engine speed of 2,500 rpm for 3 minutes.
(f) Read the output voltage of the HO2 sensor when the engine rpm is suddenly increased.
HINT:
Quickly accelerate the engine to 4,000 rpm 3 times using the accelerator pedal.
Standard:
Fluctuates between 0.4 V or less and 0.5 V or more.
| NG |
|
|
|
8. |
PERFORM CONFIRMATION DRIVING PATTERN |
|
|
9. |
READ OUTPUT DTC (DTC P0138, P0158) |
(a) On the intelligent tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
(b) Read DTCS.
Result:
|
Display (DTC Output) |
Proceed to |
|---|---|
|
P0136 or P0156 |
A |
|
No output |
B |
| B |
|
|
|
10. |
REPLACE HEATED OXYGEN SENSOR |
(a)
Replace HO2 sensor
.
|
|
11. |
PERFORM CONFIRMATION DRIVING PATTERN |
|
|
12. |
READ OUTPUT DTC (DTC P0138 or P0158) |
(a) On the intelligent tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
(b) Read DTCs.
Result:
|
Display (DTC Output) |
Proceed to |
|---|---|
|
P0136 or P0156 |
A |
|
No output |
B |
| B |
|
|
|
13. |
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME) |
(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
(b) Start the engine and turn the tester ON.
(c) Warn up the engine.
(d) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INJ VOL.
(e) Change the injection volume using the tester, monitoring the voltage output of Air Fuel Ratio (A/F) and HO2 sensors displayed on the tester.
HINT:
- Change the fuel injection volume within the range of -12% and +12%. The injection volume can be changed in 1% graduations within the range.
- The A/F sensor is displayed as AFS B1S1 (AFS B2S1), and the HO2 sensor is displayed as O2S B1S2 (O2S B2S2) on the intelligent tester.
|
Tester Display (Sensor) |
Voltage Variations |
Proceed to |
|---|---|---|
|
AFS B1S1 (AFS B2S1) (A/F) |
Alternates between more than 3.3 V and less than 3.3 V |
OK |
|
AFS B1S1 (AFS B2S1) (A/F) |
Remains at more than 3.3 V |
NG |
|
AFS B1S1 (AFS B2S1) (A/F) |
Remains at less than 3.3 V |
NG |
HINT:
- A normal HO2 sensor voltage (O2S B1S2 or O2S B2 S2) reacts in accordance with increases and decreases in fuel injection volumes. When the A/F sensor voltage remains at either less than 3.3 V or more than 3.3 V despite the HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.
| NG |
|
| OK |
|
CHECK AND REPLACE EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO (FUEL INJECTOR, FUEL PRESSURE, GAS LEAKAGE FROM EXHAUST SYSTEM, ETC.) |
|
14. |
CHECK FOR EXHAUST GAS LEAKAGE |
(a) Check for exhaust gas leakage from the exhaust manifold and pipe.
OK:
No exhaust gas leakage.
| NG |
|
|
|
15. |
INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) |
|
(a) Disconnect the H8 or H17 HO2 sensor connector. (b) Measure the resistance of the HO2 sensor connector. Standard resistance (Bank 1, 2 sensor 2):
(c) Reconnect the HO2 sensor connector. |
|
| NG |
|
|
|
16. |
INSPECT EFI RELAY (Marking: EFI OR ECD) |
|
(a) Remove the EFI relay from the engine room relay block. (b) Measure the resistance of the EFI relay. Standard resistance:
(c) Reinstall the EFI relay. |
|
| NG |
|
|
|
17. |
CHECK HARNESS AND CONNECTOR (ECM - HEATED OXYGEN SENSOR) |
(a)
Check harness and connector
.
| NG |
|
| OK |
|
|
|