engine coolant ISUZU KB P190 2007 Workshop Repair Manual

6E-166 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0404 (Flash Code 45)
Circuit Description
The ECM controls the EGR valve opening based on the
engine running condition and by controlling the EGR
solenoid. The EGR valve position is detected by the
position sensor, and relayed to the ECM. If the ECM
detects a variance between the actual EGR valve
position and desired EGR valve position for a
calibrated amount of time while the EGR valve is
commanded ON, this DTC will set.
Condition for Running the DTC • DTCs P0112, P0113, P0116, P0117, P0118, P0405, P0406, P0652, P0653, P2227, P2228 and
P2229 are not set.
• The battery voltage is between 10 to 16 volts.
• The ignition switch is ON.
• The engine coolant temperature is between 20 to 11 0 °C (68 to 230 °F).
• The intake air temperature is between 0 to 110 °C
(32 to 230 °F).
• The barometric pressure is between 60 to 120 kPa (8.7 to 17.4 psi).
• The EGR control is commanded ON. Condition for Setting the DTC
• The ECM detects that the actual EGR position is more than 10% below the desired position for 4
seconds.
Action Taken When the DTC Sets • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits EGR control.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• A sticking or intermittently sticking EGR valve may set this DTC.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0404
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0403, P0405 or P0406 also set? —
Go to Applicable DTC Go to Step 3
3 1. Perform the EGR Solenoid Control with a scan
tool several times.
2. Command the Desired EGR Position Increase and Decrease while observing the EGR
Position.
Does the EGR Position parameter follow within the
specified value quick enough (compare with a
similar unit if available)?
± 5%
Go to Diagnostic Aids Go to Step 4

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-231
DTC P1094 (Flash Code 226)
Description
The common rail fuel system is comprised of two fuel
pressure sections: a suction side between the fuel tank
and the fuel supply pump and a high-pressure side
between the fuel supply pump and the fuel injectors.
Fuel is drawn from the fuel tank via a feed pump and
then pumped into the fuel rail by two plungers, all of
which are internal to the fuel supply pump. This high
pressure is regulated by the ECM using the fuel rail
pressure (FRP) regulator dependant upon values from
the FRP sensor attached to the fuel rail.
If the ECM detects that the difference between the
actual and the desired fuel pressure is small at low
engine speed but the FRP regulator commanded fuel
flow is certain amount high, this DTC will set. (FRP
Regulator Commanded High DTC)
If the ECM detects that the fuel rail pressure is sharply
decreased when fuel cut, this DTC will also set. (Fuel
Pressure Drop DTC)
Condition for Running the DTC
FRP Regulator Commanded High DTC • DTCs P0087, P0091, P0092, P0117, P0118, P0182, P0183, P0192, P0193, P0500, P0501,
P0652, P0653, P0201 - P0204, P1064, P1065,
P124B and P2146 - P2151 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The accelerator pedal is not depressed.
• The engine coolant temperature is more than 50 °C
(122 °F).
• The vehicle speed is less than 3km/h (2MPH).
Fuel Pressure Drop DTC
• DTCs P0087, P0091, P0092, P0182, P0183, P0192, P0193, P0652, P0653, P0201 - P0204,
P1064, P1065, P124B and P2146 - P2151 are not
set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The accelerator pedal is not depressed.
• The engine speed is more than 1500RPM.
• The vehicle speed is more than 3km/h (2MPH).
Condition for Setting the DTC
FRP Regulator Commanded High DTC • The ECM detects that the FRP regulator commanded fuel flow is more than a
predetermined range for longer than 10 seconds
when the engine speed is near idle speed.
Fuel Pressure Drop DTC
• The ECM detects that the fuel rail pressure is dropped more than a threshold when the
commanded fuel is cut. Action Taken When the DTC Sets
FRP Regulator Commanded High DTC • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
Fuel Pressure Drop DTC
• The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (Euro 4 Specification)
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
(Except Euro 4 Specification)
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
• The ECM stops engine running when the vehicle speed is lower than 5 km/h (3 MPH) for 5 seconds.
The engine will run after the key is cycled when the
ignition has been tuned OFF for longer than 10
seconds.
Condition for Clearing the DTC
FRP Regulator Commanded High DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Fuel Pressure Drop DTC
• Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Diagnostic Aids • An intermittently sticking FRP regulator may have allowed the fuel pressure to become low enough to
set this DTC.
• Normal Fuel Rail Pressure readings on the scan tool with the engine running in neutral at idle is
around 27 to 33 MPa (3,900 to 4,800 psi) after
warm up.
• A skewed FRP sensor value can set this DTC. The FRP Sensor on the scan tool should read 0.9 to
1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1
minute.

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6E-246 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P1404 (Flash Code 45)
Circuit Description
The ECM controls the EGR valve opening based on the
engine running condition and by controlling the EGR
solenoid. The EGR valve position is detected by the
position sensor, and relayed to the ECM.
If the ECM detects that the actual EGR position is
higher than certain amount, this DTC will set. (Closed
Position Error DTC)
If the ECM detects a variance between the learned
closed position and actual closed position, this DTC will
also set. (Learned Position Error DTC)
Condition for Running the DTC
Closed Position Error DTC • DTCs P0112, P0113, P0116, P0117, P0118, P0404 P0405, P0406, P0652, P0653, P2227,
P2228 and P2229 are not set.
• The battery voltage is between 10 to 16 volts.
• The ignition switch is ON.
• The engine coolant temperature is between 20 to 11 0 °C (68 to 230 °F).
• The intake air temperature is between 0 to 110 °C
(32 to 230 °F).
• The barometric pressure is between 60 to 120 kPa (8.7 to 17.4 psi)
Learned Position Error DTC
• DTCs P0404, P0405 and P0406 are not set.
Condition for Setting the DTC
Closed Position Error DTC • The ECM detects that the actual EGR position is
more than 20% for 5 seconds when the EGR
control is commanded OFF.
Learned Position Error DTC
• The ECM detects that the EGR learned minimum position is more than 10% or less than -10% when
the ignition switch is OFF.
Action Taken When the DTC Sets • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits EGR control. (Closed Position Error DTC)
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• A sticking or intermittently sticking EGR valve may set this DTC.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P1404
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0403, P0405 or P0406 also set? —
Go to Applicable DTC Go to Step 3
3 1. Remove the EGR valve assembly from the
engine.
2. Inspect the EGR valve for the following conditions:
• Restricted EGR valve by foreign materials
• Excessive deposits at valve
• Bent valve shaft
3. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Step 4

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6E-290 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P2227 (Flash Code 71)
Circuit Description
The barometric pressure (BARO) sensor is located on
the intake manifold. The BARO sensor is a transducer
that varies voltage according to changes the barometric
pressure. Within the ECM, the diagnostic compares the
BARO sensor input to the boost pressure sensor input.
If the ECM detects that the inputs are not within a
specified amount of each other, this DTC will set.
Condition for Running the DTC • DTCs P0101, P0102, P0103, P0107, P0108, P0116, P0117, P0118, P0122, P0123, P0500,
P0501, P0638, P0652, P0653, P0698, P0699,
P2100, P2101, P2103, P2228 and P2229 are not
set.
AND following conditions are met for longer than 3
seconds.
• The ignition switch is ON.
• The engine coolant temperature is more than 5 °C
(41 °F).
• The engine speed is less than 800 RPM.
• The fuel injection quantity is less than a predetermined value.
• The accelerator pedal is not depressed.
• The vehicle is not running.
• The engine run time is longer than 5 seconds. Condition for Setting the DTC
• The ECM detects that the differential pressure between the barometric pressure and the boost
pressure is more than 10 kPa (1.5 psi) for 10
seconds.
Action Taken When the DTC Sets • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P2227
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0107, P0108, P2228 or P2229 also set? —
Go to Applicable DTC Go to Step 3
3 1. Turn ON the ignition, with the engine OFF.
2. Compare the Boost Pressure parameter to the Barometric Pressure (BARO) parameter with
a scan tool.
Are both parameter within the range specified of
each other? 10 kPa (1.5
psi)
Go to Diagnostic Aids Go to Step 4
4 Determine the outside barometric pressure from
your location specified in the altitude vs barometric
pressure table. Refer to Altitude vs Barometric
Pressure.
Is the BARO parameter on the scan tool close to
the outside barometric pressure? —
Go to Step 5 Go to Step 7

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6E-302 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
EGR Control System Check
Description
The EGR system recirculates a part of exhaust gas
back into the intake manifold, which results in reducing
NOx emissions. The EGR control system uses an
electronic control system to ensure both driveability
and low emission. A control current from the ECM
operates a solenoid to control the lift amount of EGR
valve. Also, an EGR position sensor is provided at the
rear of the solenoid to feed actual valve lift amount
back to the ECM for more precision control.
The EGR control starts when the conditions for engine
speed, engine coolant temperature, intake air
temperature and barometric pressure are satisfied.
Then, the valve opening is calculated according to the
engine speed, and target fuel injection quantity. Based
on this valve opening, the drive duty of the solenoid is
determined and the valve is driven accordingly. The
intake throttle valve is provided to adequate intake
manifold depression to ensure EGR gas flow. EGR Control Operation
• The engine coolant temperature (ECT) is between 5°C (41 °F) and 100 °C (212 °F).
• The intake air temperature (IAT) is more than 5 °C
(41 °F).
• The barometric pressure (BARO) is more than 90kPa (13psi).
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing EGR Control System Check
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Monitor the DTC Information with a scan tool.
Are any DTCs set in which the “Action Taken When
the DTC Sets” under that particular code states,
“The ECM inhibits EGR control”? —
Refer to Applicable DTC Go to Step 3

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-303
31. Inspect the following conditions:
• An EGR valve gasket that is missing ordamaged
• A sticking EGR valve
• EGR gas leakage any of the EGR passage between the exhaust manifold
and intake manifold
• Restricted or collapsed EGR passage between the exhaust manifold and the
EGR valve
• Any type of restriction in the exhaust system
• Restricted air cleaner element, restricted or collapsed air tubing between the air
cleaner and the intake manifold
• Any air induction leak
• Any water intrusion in the induction system
• Any contamination or objects that block the MAF sensor inlet
• Skewed or slow MAF sensor
• Skewed engine coolant temperature (ECT) sensor. Refer to Temperature vs
Resistance table to test the ECT sensor
at various temperature levels to evaluate
the possibility of a skewed sensor.
• Skewed barometric pressure (BARO) sensor. Determine the outside barometric
pressure from you location specified in
the altitude vs barometric pressure table.
Refer to Altitude vs Barometric Pressure.
• A sticking intake throttle valve
2. Repair the condition as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 4
4 1. Place the transmission in Neutral and set the
parking brake.
2. Start the engine and warm up (arrow engine coolant temperature to reach at least 60 °C
[140 °F]).
3. Accelerate the engine between idle and W.O.T (accelerator pedal full travel) many
times while observing the Desired EGR
Position and EGR Position parameter with a
scan tool.
Does the EGR Position parameter follow within the
specified value? ±
5%
Go to Step 5 Go to Step 8
5 1. Perform the EGR Solenoid Control with a scan
tool several times.
2. Command the Desired EGR Position Increase and Decrease while observing the EGR
Position.
Does the EGR Position parameter follow within the
specified value quick enough? ±
5%
Go to Step 6 Go to Step 8
Step
Action Value(s)Yes No

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6E-306 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Glow Control System Check
Description
The glow control system consists of the ECM, the glow
relay, the glow indicator lamp and glow plugs. The glow
control system is operated when the engine coolant
temperature is low, which allows easier engine starting.
The ECM commands the glow relay ON for a certain
length of time at ignition switch is ON with engine OFF.
In after glow phase, the glow plugs remain energized
for a certain period with engine run.
Glow Control Operation • The glow indicator lamp illuminates between 0.5 seconds to 7 seconds depending upon the engine
coolant temperature. • The pre glow control system operates when the
engine coolant temperature is less than 30 °C
(86 °F).
• The after glow control system operates when the engine coolant temperature is less than 60 °C
(140 °F).
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Glow Control System Check (1 of 2)
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Monitor the DTC Information with a scan tool.
Is DTC P0117, P0118 or P0380 set? —
Refer to Applicable DTC Go to Step 3
3 Notice:
If no glow indicator lamp is equipped, skip
to Step 3.
1. Verify whether the instrument panel (IP) cluster is operational.
2. Perform the Glow Plug Lamp Control with a scan tool.
3. Command the lamp ON and OFF.
Does the glow indicator lamp turn ON and OFF
with each command? —
Go to Step 4 Go to 2 of 2 Step 1
4 1. Turn OFF the ignition.
2. Make sure the metal bus bar that connects switched battery voltage supply terminal (E-
49) and all glow plugs is secured tightly.
3. Turn ON the ignition, with the engine OFF
4. Connect a test lamp between the metal bus bar (glow plug power supply E-49 terminal)
and a known good ground.
5. Perform the Glow Relay Control with a scan tool.
6. Command the relay ON while observing the test lamp.
Does the test lamp turn ON only when commanded
ON? —
Go to Step 5 Go to Step 6

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6E-328 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Hard Start
ChecksAction
Definition:
The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but immediately dies.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Ensure the driver is using the correct starting procedure.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect that the harness connectors are correctly connected.
• Inspect the fuel type and quality.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not damaged.
• Camshaft position (CMP) sensor is tight and the timing chain sprocket is not damaged.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to Fuel System Check chart
and appropriate procedure in the Fuel System section.
• Air in the fuel system.
• Water contamination in the fuel.
• Fuel waxing or icing.
• Fuel filter indicator lamp is continuously or frequently turned ON with engine run.
• External fuel leaks or high engine oil level.
• In-tank fuel pump operation. Refer to In-tank Fuel Pump System Check in this section.
• Fuel leak off from the fuel pressure limiter valve and fuel injectors.
• Fuel lines between the fuel tank and fuel supply pump for being crushed, kinked, tightness, cracks and plugged.
• A plugged fuel tank vent valve and hose.
• Inside the fuel tank for any foreign material that may be getting drawn into the fuel line pickup causing a blocked condition.
• Fuel supply pump operation.
Notice: The fuel supply pump must be timed to the engine and adjustment value must
be learned to the ECM.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Injector Force Drive with a scan tool.
• Observe the FRP Regulator Feedback current on the scan tool.

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6E-330 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Rough, Unstable, or Incorrect Idle and Stalling
ChecksAction
Definition:
Engine runs unevenly at idle. If severe, the engine or vehicle may shake. Engine idle speed may vary in RPM. Either condition
may be severe enough to stall the engine.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or restricted. Replace as necessary.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect that the harness connectors are correctly connected.
• Inspect the fuel type and quality.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure parameter at idle in Neutral. The Fuel Rail Pressure should always be within 27 to 33 MPa (3,900 to 4,800 psi) after warm up.
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not damaged.
• Camshaft position (CMP) sensor is tight and the timing chain sprocket is not damaged.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to Fuel System Check Chart
and appropriate procedure in the Fuel System section.
• Air in the fuel system.
• Water contamination in the fuel.
• Fuel waxing or icing.
• Fuel filter indicator lamp is continuously or frequently turned ON with engine run.
• External fuel leaks or high engine oil level.
• In-tank fuel pump operation. Refer to In-tank Fuel Pump System Check in this section.
• Fuel leak off from the fuel pressure limiter valve and fuel injectors.
• Fuel lines between the fuel tank and fuel supply pump for being crushed, kinked, tightness, cracks and plugged.
• A plugged fuel tank vent valve and hose.
• Inside the fuel tank for any foreign material that may be getting drawn into the fuel line pickup causing a blocked condition.
• Fuel supply pump operation.
Notice: The fuel supply pump must be timed to the engine and adjustment value must
be learned to the ECM.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Injector Force Drive with a scan tool.
• Observe the Fuel Compensation for each cylinder at idle on the scan tool.
• Observe the FRP Regulator Feedback current on the scan tool.

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6E-332 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
High Idle Speed
ChecksAction
Definition:
Engine idle speed is higher than normal in regardless of engine coolant temperature.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Inspect that the harness connectors are correctly connected.
• Use the scan tool to compare the engine speed and tachometer on the instrument panel (IP) cluster.
• Inspect the battery voltage. If the battery voltage is less than 11 volts, the ECM set the idle speed 50RPM higher than normal.
• Inspect the A/C operation.
• Inspect the fuel type and quality.
• Inspect the engine oil level.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure parameter at idle in Neutral. The Fuel Rail Pressure should always be within 27 to 33 MPa (3,900 to 4,800 psi) after warm up.
• Observe the Accelerator Pedal Position (APP). APP parameter should change linearly from 0 to 100% according to the accelerator pedal operation.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to the Fuel System section.
• Fuel injectors. Remove the injectors and visually inspect. (Injector tip(s) may be damaged)

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