Page 2057 of 6000
6E–164
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1588 – Brake SW Malfunction
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
21. 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 the “DTC” info for DTC
P1588.
Does the Tech 2 indicate DTC P1588 failed?
—Go to Step 3
Refer to
Diagnostic
Aids
3Check the Brake SW circuit for a poor connection and
replace the terminal if necessary.
Did the terminal require replacement?
—Verify repairGo to Step 4
4Replace the Brake SW.
Is the action complete?
—Verify repair—
Page 2058 of 6000

6E–165 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0601 (Flash DTC 55)
ECM Checksum Error
Action Taken When the DTC Sets
The ECM will not illuminate the malfunction indicator
lamp (MIL).
The ECM will store conditions which were present
when the DTC was set in the Failure Records data only.
Conditions for Clearing the MIL/DTC
DTC P0601 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.
Diagnostic Aids
DTC P0601 indicates that the contents of the
EEPROM have changed since the ECM was
programmed. The only possible repair is ECM
replacement. Remember to program the replacement
ECM with the correct software and calibration for the
vehicle.
DTC P0601 – ECM Checksum Error
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
2Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—
Page 2059 of 6000

6E–166
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0650 (Flash DTC 77)
Check Engine Lamp Circuit Open/Short
060RW136
Circuit Description
The check engine lamp circuit receives through Meter
10A fuse the battery, current flowing in the order of Meter
and check engine lamp.
Action Taken When the DTC Sets
The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the 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 P0650 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
lamp test display on the Tech 2 while moving
connectors and wiring harnesses related to the check
engine lamp. A change in the display will indicate the
location of the fault.
If the Tech 2 indicate DTCs P0650 and P0381, check the
meter circuit necessarily.
Page 2060 of 6000

6E–167 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0650 – Check Engine Lamp Open/Short
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
21. Ignition “ON,” engine “OFF.”
2. Observe the “Lamp Test” display on the Tech 2.
Is the “Lamp Test” operating?
—
Refer to
Diagnostic
Aids
Go to Step 3
31. 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 the “DTC” info for DTC
P0650.
5. If the Tech 2 indicate DTCs P0650 and P0381,
check the meter circuit necessarily.
Does the Tech 2 indicate DTC P0650 failed?
—Go to Step 4
Refer to
Diagnostic
Aids
4Check the Check Engine Lamp circuit for a poor
connection at the Meter and replace the bulb if
necessary.
Did the bulb require replacement?
—Verify repairGo to Step 5
5Using the Tech 2.
Does the Tech 2 indicate DTC P0650 failed?
—Go to Step 6—
6Check the Meter circuit for a poor connection.
Did the Meter require repair?
—Verify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—
Page 2061 of 6000

6E–168
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0654 (Flash DTC 27)
Tachometer Circuit Open/Short
060RW136
Circuit Description
The Tach Meter circuit receives through Meter 10A fuse
from the battery, current flowing in the order of Mater and
the Tach Meter.
Action Taken When the DTC Sets
The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the 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 P0650 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 Tech 2 indicat DTCs 0654, P0650 and P0381,
Check the meter circuit necessarily.
Page 2062 of 6000

6E–169 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0654 – Tachometer Circuit Open/Short
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
21. 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 the “DTC” info for DTC
P654.
Does the Tech 2 indicate DTC P0654 failed?
—Go to Step 3
Refer to
Diagnostic
Aids
3Check the Tach meter circuit for a poor connection at
the Meter and replace the terminal if necessary.
Did the terminal require replacement?
—Verify repairGo to Step 4
4Using the Tech 2.
Does the Tech 2 indicate DTC P0654 failed?
—Verify repairGo to Step 5
5Check the Tach Meter circuit for a poor connection.
Did the terminal require replacement?
—Verify repairGo to Step 6
6Replace the tachometer.
Is the action complete?
—Verify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—
Page 2063 of 6000

6E–170
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1655 (Flash DTC 17)
Thermo Relay Circuit Open/Short
060RW130
Circuit Description
The thermo relay circuit receives current through air con
10A fuse from the battery, current flowing in the order of
the thermo relay and thermo SW.
Action Taken When the DTC Sets
The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the 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 P1655 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.
Page 2064 of 6000

6E–171 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1655 – Thermo Relay Circuit Open/Short
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
21. Ignition “ON,” engine “OFF.”
2. Observe the “Batteri Voltage” display on the Tech 2.
Is the “Batteri Voltage” below the specified value?
11 VGo to Step 4Go to Step 3
31. 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 the “Specific DTC” info for
DTC P1655.
Does the Tech 2 indicate DTC P1655 failed?
—Go to Step 4
Refer to
Diagnostic
Aids
4Check the Thermo Relay circuit for a poor connection
and replace the terminal if necessary.
Did the terminal require replacement?
—Verify repairGo to Step 5
5Check the Thermo Relay for damage.
Did the Thermo Relay require replacement?
—Verify repairGo to Step 6
6Check the Thermo Relay circuit for a poor connection
at the ECM and replace the terminal if necessary.
Did the terminal require replacement?
—Verify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—