INSPECT INTAKE SYSTEM
Check that there is no air suction or leaks at the points shown in the illustration.
For engine room area:
| *A | for RHD | - | - |
For engine area:
CHECK INTAKE AIR CONTROL SYSTEM
Check for leakage or clogging between the air cleaner housing and turbocharger inlet, and between the turbocharger outlet and cylinder head.
| Condition | Operation |
|---|---|
| Clogged air cleaner | Clean or replace element |
| Hoses collapsed or deformed | Repair or replace |
| Leakage from connections | Check each connection and repair |
| Cracks in components | Check and repair or replace |
CHECK EXHAUST SYSTEM
Check for leakage or clogging between the cylinder head and turbocharger inlet and between the turbocharger outlet and exhaust pipe.
| Condition | Operation |
|---|---|
| Deformed components | Repair or replace |
| Foreign material in passages | Remove |
| Leakage from components | Repair or replace |
| Cracks in components | Check and repair or replace |
CHECK BOOST PRESSURE
Connect the intelligent tester to the DLC3.
Start the engine and turn the tester on.
Warm up the engine.
Tech Tips
Be sure to perform the inspection when the engine coolant temperature is between 75 and 90°C (167 and 194°F).
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.
| *1 | Snapshot Record Button |
Take a snapshot of the Data List items with the intelligent tester shown in the illustration.
Tech Tips
Graphs can be displayed by transferring the stored snapshot from the tester to a PC. Intelligent Viewer must be installed on the PC.
The condition of the turbocharger can be determined by fully depressing the accelerator pedal while driving at 15 km/h (9 mph) in 2nd gear to accelerate the vehicle (obey all laws and regulations, and pay attention to driving conditions while driving the vehicle), and then comparing MAP with Target Booster Pressure at an engine speed of 3000 rpm.
Compare MAP with Target Booster Pressure.
Tech Tips
The specification below denote the difference between the absolute pressure values.
| Standard |
|---|
| MAP is within 25 kPa of Target Booster Pressure when accelerating with accelerator pedal fully depressed. |
Tech Tips
If the driving inspection using the intelligent tester above cannot be performed (e.g. due to road conditions), perform the following inspection.
Warm up the engine.
Tech Tips
Be sure to perform the inspection when the engine coolant temperature is between 75 and 90°C (167 and 194°F).
| *1 | Gas Filter |
| *2 | Manifold Absolute Pressure Sensor |
| *3 | 3-Way Connector |
Using a 3-way connector, connect SST (turbocharger pressure gauge) between the manifold absolute pressure sensor and the gas filter.
While depressing the clutch pedal, fully depress the accelerator pedal down. Measure the boost pressure at maximum engine speed (5100 to 5250 rpm).
| Standard pressure (Gauge Pressure) |
|---|
| 38 to 61 kPa (0.4 to 0.6 kgf/cm2, 5.5 to 8.8 psi) |
If the pressure is lower than the standard, the following problems may be present.
The intake system or exhaust system has leakage or blockage.
The vacuum hose connected to the turbocharger actuator is cracked or disconnected.
The turbocharger sub-assembly or vacuum regulating valve assembly is malfunctioning.
The EGR valve does not close.
The diesel throttle body does not open.
The vacuum hose connected to the manifold absolute pressure sensor is cracked or disconnected.
The mass air flow meter is malfunctioning.
A fuel injector assembly is malfunctioning.
If the pressure is higher than the standard, check the turbocharger and vacuum regulating valve.
Chart showing the suspected trouble areas when the pressure is lower than the standard.
Tech Tips
○: If a problem listed in the leftmost column of the chart exists, or if the part in the leftmost column of the chart has a malfunction, the value of the Data List item in the uppermost row of the chart will meet the conditions shown in the row labeled "Value which represents a malfunction".
The values in the chart are applicable when the engine coolant temperature is between 75 and 90°C (167 and 194°F).
The values in the chart are valid in an area with an absolute atmospheric pressure higher than 95 kPa. (Standard atmospheric pressure is 101 kPa. Atmospheric pressure decreases by 1 kPa for every 100 m increase in altitude, and is also affected by the current weather conditions.)
When the altitude increases, atmospheric pressure and MAP decrease.
| Item | MAP (Absolute pressure inside intake manifold) |
MAF (Intake air flow rate) |
Accel Position | Actual Throttle Position | Actual EGR Valve Pos. | EGR Close Lrn. Status (EGR valve fully closed position learning status) |
Fuel Pressure | Injection Feedback Val #1 (to #4) |
|---|---|---|---|---|---|---|---|---|
| Values taken from an actual normal vehicle *1 |
- | 117 g/sec | 99.60% | 0% | 0% | OK | - | -3 to +3 mm3/ st |
| Values which represent a malfunction *1 |
MAP is lower than Target Booster Pressure by 25 kPa or more | MAF is less than 90 g/sec | Accel Position is less than 90% *2 |
Actual Throttle Position is not within 5% of Target Throttle Position | Actual EGR Valve Pos. is more than 5% *3 |
NG (Determined after performing learning) |
Fuel Pressure is lower than Target Common Rail Pressure by 10 MPa or more (Check while steady condition) | Outside of above range |
| Turbocharger | ○ | ○ | - | - | - | - | - | - |
| Turbocharger actuator hose is disconnected | ○ | ○ | - | - | - | - | - | - |
| E-VRV | ○ | ○ | - | - | - | - | - | - |
| EGR valve does not close or has problem with movement | ○ | ○ | - | - | ○ (Problem with EGR valve movement) *4 |
○ (EGR valve does not close) *4 |
- | - |
| Problem with diesel throttle movement | ○ (Intake airflow decreases) |
○ | - | ○ | - | - | - | - |
| Accelerator pedal cannot be fully depressed or problem with accelerator pedal position sensor exists | - | ○ | ○ | - | - | - | - | - |
| Intake air system leakage or blockage | ○ | ○ | - | - | - | - | - | - |
| Exhaust gas leakage before turbocharger or blockage | ○ | ○ | - | - | - | - | - | - |
| Manifold absolute pressure sensor | ○ | ○ | - | - | - | - | - | - |
| Manifold absolute pressure sensor hose is disconnected | ○ | ○ | - | - | - | - | - | - |
| Mass air flow meter | - | ○ | - | - | - | - | - | - |
| Fuel system (injector, supply pump or common rail) |
○ | ○ | - | - | - | - | ○ (Fuel injector leakage, decrease in pressure discharge valve relief pressure or valve is stuck) |
○ *5 |
Tech Tips
*1: These values are measured when the transmission is in 2nd gear, the accelerator pedal is fully depressed, the vehicle is accelerating, and the engine speed is 3000 rpm.
*2: The Accel Position is the accelerator opening angle (%) for engine control use. The value indicates 99.60% when the accelerator pedal fully depressed. If the value indicates less than 90% when the accelerator pedal fully depressed, the accelerator pedal position sensor circuit or the pedal itself is malfunctioning. When the MIL is illuminated, even with the accelerator pedal fully depressed and an Accel Position of below 70%, it means the fail-safe is restricting the accelerator.
*3: Check that the Actual EGR Valve Pos. is around 0% when the Target EGR position value indicates 0%. The EGR valve may be malfunctioning if the value is stuck or does not fluctuate smoothly. However, in some cases the EGR valve may be malfunctioning even if the Actual EGR Valve Pos. value is normal. Inspect the EGR valve for any defects (deposits, valve stuck, poor movement, etc.) if necessary.
*4: DTC P0400 may be stored at this time. If the actual EGR valve position follows the target EGR valve position slowly, a feeling of hesitation may occur.
*5: If Injection Feedback Val # of a cylinder is not within -3 to +3 mm3/st, the corresponding cylinder may have a malfunction (injector or compression). However, in some cases the cylinder may be malfunctioning even if the value is within -3 to +3 mm3/st because these values are injection volume correction values calculated by the ECM at the engine idling and not correction values for the high engine load condition related to the boost pressure control and engine output performance.
CHECK TURBOCHARGER SUB-ASSEMBLY
CAUTION:
Wear protective gloves to prevent injuries and burns when checking the turbocharger.
The engine compartment becomes hot when the engine is running.
Remove the No. 1 engine cover.
Disconnect the vacuum hose from the actuator.
Connect a vacuum pump to the actuator.
Check that the rod moves toward the actuator when vacuum is applied to the actuator.
If the rod does not move, replace the turbocharger sub-assembly.
Reconnect the vacuum hose to the actuator.
Reinstall the No. 1 engine cover.