Isuzu KB P190. Manual - part 460

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-223

Circuit/ System Testing DTC P1065

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 6

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

Step

Action

Value(s)

Yes

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Turn ON the ignition, with the engine OFF.

Monitor the DTC Information with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic

Aids

Is DTC P0091 or P0092 also set?

—

Go to Applicable

DTC

Go to Step 4

Observe the Fuel Rail Pressure (FRP) Regulator
Feedback parameter with a scan tool.

Is the scan tool parameter more than the specified
value?

300 mA

Go to Step 7

Go to Step 5

Turn OFF the ignition for 30 seconds.

Disconnect the FRP regulator harness
connector.

Connect a test lamp between the high side
circuit (pin 1 of E-50) and a known good
ground.

Turn ON the ignition, with the engine OFF. DO
NOT start the engine.

Does the test lamp illuminate then go out?

—

Go to Step 6

Go to Step 8

Turn OFF the ignition for 30 seconds.

Connect a test lamp between the low side
circuit (pin 2 of E-50) and battery voltage.

Turn ON the ignition, with the engine OFF. DO
NOT start the engine.

Does the test lamp illuminate then go out?

—

Go to Step 10

Go to Step 9

6E-224 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Test the high side circuits between the ECM
(pins 34 and 54 of E-90) and the FRP
regulator (pin 1 of E-50) for a short to battery
or ignition voltage.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 13

Test the high side circuits between the ECM
(pins 34 and 54 of E-90) and the FRP
regulator (pin 1 of E-50) for the following
conditions:

• An open circuit

• A short to ground

• A short to the low side circuit

• High resistance

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 11

Test the low side circuits between the ECM
(pins 50 and 70 of E-90) and the FRP
regulator (pin 2 of E-50) for the following
conditions:

• An open circuit

• High resistance

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 11

Inspect for an intermittent and for poor
connections at the harness connector of the
FRP regulator (pins 1 and 2 of E-50).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 12

Turn OFF the ignition.

Disconnect the ECM harness connector.

Inspect for an intermittent and for poor
connections at the harness connector of the
ECM (pins 34, 50, 54 and 70 of E-90).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 13

Replace the FRP regulator. Refer to Fuel Pump
Replacement.

Did you complete the replacement?

—

Go to Step 14

—

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 14

—

Step

Action

Value(s)

Yes

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-225

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 15

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

Step

Action

Value(s)

Yes

6E-226 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC P1093 (Flash Code 227)

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 fuel rail pressure is certain pressure
lower than the desired pressure, this DTC will set.

Condition for Running the DTC

• DTC P0087, P0091, P0092, 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 engine is running.

• The FRP regulator commanded fuel flow is more

than a threshold.

Condition for Setting the DTC

• The ECM detects that the actual fuel rail pressure

is more than 10 to 20 MPa (1,450 to 2,900 psi)
below the desired pressure for longer than 5
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 cruise control.

Condition for Clearing the DTC

• Refer to DTC Type Definitions for Condition for

Clearing the MIL/ DTC - Type A.

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.

Notice:

• This DTC most likely indicates a loss of fuel

pressure by a restricted suction side fuel line.
Inspect the suction side fuel restriction between
the fuel supply pump and the fuel tank.

• If the fuel tank is empty or near empty, air might be

allowed to go into the fuel system. With air in the
fuel system, smooth flow of fuel into the supply
pump is interrupted and this DTC may set. Perform
bleeding of fuel system after refilling.

Schematic Reference: Fuel System Routing Diagram
and Engine Controls Schematics

Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views

Circuit/ System Testing DTC P1093

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Monitor the DTC Information with a scan tool.

Is DTC P0087, P0091, P0092, P0192, P0193,
P0201 - P0204, P1064, P1065, P1094, P124B or
P2146 - P2151 set?

—

Go to Applicable

DTC

Go to Step 3

Content .. 458 459 460 461 ..