6E–70
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0121 (Flash DTC 33)
AP Sensor Rationality
060RW134
Circuit Description
The accel position (AP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle.
The AP signal is one of the most important inputs used by
the Engine Control Module ECM for fuel volume control
and many of the ECM-controlled outputs. If the ECM
detects an out-of-range condition, DTC P0121 will set.
Action Taken When the DTC Sets
The ECM will illuminate the malfunction indicator lamp
(MIL) after fault is detected.
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
DTC P0121 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:
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.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
ECT 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 P0121 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
6E–72
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0122 (Flash DTC 21)
AP Sensor Low Voltage
060RW134
Circuit Description
The accelerator position (AP) sensor circuit provides a
voltage signal that changes relative to throttle blade
angle.
The AP signal is used by the Engine Control Module ECM
for fuel volume control and many of the ECM-controlled
outputs.
Action Taken When the DTC Sets
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
DTC P0122 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:
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.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
throttle position display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor. A change in the display will indicate the
location of the fault.
If DTC P0122 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
DTC P0122 –AP Sensor Low Voltage
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
2Check the AP sensor signal circuit.
Was the AP sensor signal circuit open or darmage?
—
Replace the
APS circuit
Go to Step 3
6E–75 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0123 (Flash DTC 21)
AP Sensor High Voltage
060RW134
Circuit Description
The accelerator position (AP) sensor circuit provides a
voltage signal that changes relative to throttle blade
angle.
The TP signal is one of the most important inputs used by
the Engine Control Module ECM for fuel volume control
and many of the ECM-controlled outputs.
Action Taken When the DTC Sets
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
DTC P0123 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:
Poor connection at ECM – Inspect harness connectors
for backed-out terminals, improper mating, brokenlocks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
AP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor. A change in the display will indicate the
location of the fault.
Faulty AP sensor – With the ignition key “ON,” engine
“OFF,” observe the AP sensor display on the Tech 2
while slowly depressing the accelerator to wide open
throttle. If a voltage over 4.88 volts is seen at any point
in normal accelerator travel, replace the AP sensor.
If DTC P0123 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number (s) below refer to the step number(s) on the
Diagnostic Chart.
8. Components that share the AP sensor 5 volt reference
“A” circuit include the following device:
6E–78
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0182 (Flash DTC 15)
FT Sensor Low Voltage
060RW129
Circuit Description
The fuel temperature (FT) sensor is a thermistor mounted
on a coolant crossover pipe at the rear of the engine. The
Engine Control Module ECM applies a voltage (about 5
volts) through a pull-up resistor to the FT signal circuit.
When the fuel is cold, the sensor (thermistor) resistance
is high, therefore the ECM will measure a high signal
voltage. As the fuel warms, the sensor resistance
becomes lower, and the FT signal voltage measured at
the ECM drops.
Action Taken When the DTC Sets
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
DTC P0182 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:
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.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
FT display on the Tech 2 while moving connectors and
wiring harnesses related to the FT sensor. A change
in the FT display will indicate the location of the fault.
If DTC P0182 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.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
6E–80
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0183 (Flash DTC 15)
FT Sensor High Voltage
060RW129
Circuit Description
The fuel temperature (FT) sensor is a thermistor mounted
in on a coolant crossover pipe at the rear of the engine.
The Engine Control Module ECM applies a voltage (about
5 volts) through a pull-up resistor to the FT signal circuit.
When the fuel is cold, the sensor (thermistor) resistance
is high, therefore the ECM will measure a high signal
voltage. As the fuel warms, the sensor resistance
becomes less, and the FT signal voltage measured at the
ECM drops.
Action Taken When the DTC Sets
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
DTC P0183 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:
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.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
FT display on the Tech 2 while moving connectors and
wiring harnesses related to the FT sensor. A change
in the FT display will indicate the location of the fault.
If DTC P0182 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
6E–82
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0192 (Flash DTC 63)
Rail Pressure Sensor Low 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 low, DTC P0192 will be
set.
Action Taken When the DTC Sets
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
DTC P0192 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:
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.
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 P0192 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 P0192 Diagnostic Chart may isolate
the cause of the fault.
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
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
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:
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.
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–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
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
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:
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.
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.