Isuzu Trooper (1998-2002 year). Manual - part 609

6E–84

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0193 (Flash DTC 63) 

Rail Pressure Sensor High Voltage

060RW135

Circuit Description

The rail pressure (RP) sensor responds to changes in oil
manifold pressure.
The ECM monitors the RP signals for voltages outside the
normal range of the RP sensor.  If the ECM detects a RP
signal voltage that is excessively high, DTC P0193 will be
set.

Action Taken When the DTC Sets

D

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

Conditions for Clearing the MIL/DTC

D

DTC P0193 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
RP display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor.  A change in the
display will indicate the location of the fault.

If DTC P0193 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set. If
it is determined that the DTC occurs intermittently,
performing the DTC P0193 Diagnostic Chart may isolate
the cause of the fault.

6E–85

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0193 – RP Sensor High Voltage

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “ DTC” info for DTC P0108.

Does the Tech 2 indicate DTC P0108 failed this
ignition?

—

Go to 

Step 3

Refer to

Diagnostic

Aids

3

Check the RP sensor signal circuit.

Was the RP sensor signal circuit open or darmage?

—

Replace the

RP circuit

Go to 

Step 4

4

Probe the sensor ground circuit with a test light to B+.

Is the test light “ON?”

—

Go to 

Step 5

Go to 

Step 7

5

1. Check the RP signal circuit for a short to voltage or a

short to the 5 volt reference “J1” circuit.

2. If the RP sensor signal circuit is shorted, repair

circuit as necessary.

Was the RP sensor signal circuit shorted?

—

Verify repair

Go to 

Step 6

6

1. Check for a poor sensor ground terminal connection

at the RP sensor electrical connector.

2. If a problem if found, replace the faulty terminal.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 7

7

1. Check for a poor sensor ground terminal connection

at the ECM.

2. If a problem is found, replace the faulty terminal.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 8

8

1. Check the continuity of the RP sensor ground

circuit.

2. If the RP sensor ground circuit measures over 5

ohms, repair open or poor connection.

Was a condition found and corrected?

—

Verify repair

Go to 

Step 9

9

Replace the ECM (Refer to the Data Programming in
Case of ECM change).

Is the action complete?

—

Verify Repair

—

6E–86

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1193 (Flash DTC 64) 

RPCV Circuit Open/Short

060RW135

Circuit Description

The rail pressure control valve (RPCV) is built in the high
pressure oil circuit.
RPCV is an important device which is used to control oil
pressure in the HEUI system.
The circuit receives current through Engine 15A fuse from
the battery, current flowing in the order of RPCV.

Action Taken When the DTC Sets

D

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

Conditions for Clearing the MIL/DTC

D

DTC P1193 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
RPCV display on the Tech 2 while moving connectors
and wiring harnesses related to the RPCV.  A change
in the RPCV display will indicate the location of the
fault.

If DTC P1193 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently.

6E–87

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P1193 – RPCV  Circuit Open/Short

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “ON.”
2. Observe the “Rail Oil Pressure” display on the Tech

2.

Is the “Rail Oil Pressure” below the specified value?

3.5 

∼

 5 Mpa

Go to 

Step 4

Go to 

Step 3

3

Replace the RPCV.

Is the action complete?

—

Go to 

Step 2

—

4

1. Engine “On”.
2. Using the Tech 2, operate “RPCV”.
3. Check the combustion noise.

Was the combustion noise change?

—

—

Go to 

Step 5

5

Check the RPCV circuit. (Fuse 15A to J1-14)

Was the RPCV circuit damaged?

—

Go to 

Step 6

Go to 

Step 7

6

Repair the RPCV circuit.

Is the action complete?

—

Verify repair

—

7

Replace the ECM (Refer to the Data Programming in
Case of ECM change).

Is the action complete?

—

Verify repair

Go to 

Step 8

8

Replace the high pressure oil pump.

Is the action complete?

—

Verify repair

—