Dtc P0192 Or P0193 (Flash Code 245) - Isuzu N 2008 Series Workshop Manual

1A-118 Engine Control System (4JJ1)

DTC P0192 or P0193 (Flash Code 245)

Circuit Description
The fuel rail pressure (FRP) sensor is installed to the
fuel rail and it detects the fuel pressure in the fuel rail,
converts the pressure into a voltage signal, and sends
the signal to the ECM. The sensor has the following
circuits.
• 5 volts reference circuit
• Low reference circuit
• FRP sensor signal circuit
The ECM monitors the FRP sensor signal voltage.
Higher fuel rail pressure provides higher signal voltage
while lower pressure provides lower signal voltage. The
ECM calculates actual fuel rail pressure (fuel pressure)
from the voltage signal and uses the result in fuel
injection control and other control tasks. If the ECM
detects an excessively low or high signal voltage, DTC
P0192 or P0193 will set.
Condition for Running the DTC
• DTCs P060B and P0651 are not set.
• The battery voltage is between 18 to 32 volts.
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the FRP sensor signal
voltage is less than 0.7 volts. (DTC P0192)
Circuit/ System Testing DTC P0192
Step
Did you perform the Diagnostic System Check -
1
Engine Controls?
1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
2
4. Monitor the DTC Information with a scan tool.
Is DTC P0651 also set?
Observe the Fuel Rail Pressure (FRP) Sensor
parameter with a scan tool.
3
Is the FRP Sensor parameter less than the
specified value?
1. Turn OFF the ignition.
2. Disconnect
connector.
4
3. Turn ON the ignition, with the engine OFF.
Is the FRP Sensor parameter more than the
specified value?
Connect a DMM between the 5 volts reference
circuit (pin 3 of E19) and a known good ground.
5
Is the DMM voltage more than the specified value?
Action
the FRP sensor harness
• The ECM detects that the FRP sensor signal
voltage is more than 4.5 volts. (DTC P0193)
Action Taken When the DTC Sets
• The ECM illuminates MIL when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type A.
• The ECM uses a FRP substitution of default value.
• The ECM limits fuel injection quantity
• The ECM inhibits pre injection.
• The ECM inhibits EGR 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.
• Electromagnetic
intermittent condition.
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Value(s) Yes
—
Go to Step 2
—
Go to DTC P0651
0.7 volts
Go to Step 4
4.5 volts
Go to Step 5
4.5 volts
Go to Step 8
interference may
No
—
Go to Step 3
Go to Diagnostic
Aids
Go to Step 6
Go to Step 7
affect