
3.HIGH RESISTANCE IN CIRCUIT
Turn the ignition off.
Disconnect the ECM harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance between the (K2) temperature sensor signal
and (K914) return circuit at the ECM harness connector with the coolant
temp sensor harness connected.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 6
No>>
Go To 4
4.(K2) SIGNAL CIRCUIT OPEN
Disconnect the coolant temperature sensor harness connector.
Measure the resistance of the (K2) coolant temperature sensor signal
circuit between the coolant temperature sensor connector and the ECM
connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 5
No>>
Repair or replace the open (K2) signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

5.(K914) SENSOR RETURN CIRCUIT OPEN
Measure the resistance of the (K914) coolant temperature sensor return
circuit between the coolant temperature sensor connector and the ECM
connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 6
No>>
Repair or replace the open (K914) sensor return circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
6.(K2) SIGNAL CIRCUIT SHORTED
Measure the resistance of (K2) signal circuit to all other circuits at the
ECM harness connector.
Istheresistancemorethan100kohms?
Ye s>>
Go To 7
No>>
Repair or replace the (K2) coolant temperature sensor sig-
nal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

P0128-THERMOSTAT RATIONALITY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
While the engine is running.
Set Condition:
The coolant temperature does not rise by a calibrated amount over a calibratedamountoftime.
Possible Causes
COOLING FAN
COOLANT TEMPERATURE SENSOR
THERMOSTAT
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.COOLING FAN
NOTE: refer to the no trouble code test*Fan Operation Testto ensure the fan is operating properly.
Is the cooling fan operating properly?
Ye s>>
Go To 2
No>>
Repair the cooling fan.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.COOLANT TEMPERATURE SENSOR
Operate the engine for 10 minutes while monitoring the coolant temperaturewiththescantool.
Did the coolant temperature change over time while the engine was running?
Ye s>>
Go To 3
No>>
Replace the coolant temperature sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
3.THERMOSTAT
NOTE: refer to the no trouble code test*Thermostat Testto ensure the thermostat is operating properly.
is the thermostat operating properly?
Ye s>>
Te s t C o m p l e t e .
No>>
Replace the thermostat.
Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

For a complete wiring diagramRefer to Section 8W.
When Monitored:
While the engine is running. .
Set Condition:
The engine coolant temperature is above a calibrated value for a calibratedamountoftime.
Possible Causes
ECT SENSOR
OTHER DTC’S
MECHANICAL FAILURE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
With the scan tool, read DTCs.
Are other Cooling system DTC’s present?
Ye s>>
Trouble shoot the other DTC’s first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.ECT SENSOR
Allow the engine to reach normal operating temperature.
Use a temperature probe and measure the engine temperature near the ECT Sensor.
With the scan tool, read the Engine Temperature.
Compare the temperature probe reading with the scan tool reading.
Are the readings within 10° of each other?
Ye s>>
Repair the cause of mechanical failure.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Replace the coolant temp sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

page page
ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10
DIAGNOSIS AND TESTING
PRE-DIAGNOSTIC TROUBLESHOOTING
PROCEDURE............................. 1606
INTERMITTENT CONDITION ............... 1607
P0031-O2 SENSOR 1/1 HEATER CIRCUIT
LOW..................................... 1608
P0032-O2 SENSOR 1/1 HEATER CIRCUIT
HIGH.................................... 1612
P0051-O2 SENSOR 2/1 HEATER CIRCUIT
LOW..................................... 1616
P0052-O2 SENSOR 2/1 HEATER CIRCUIT
HIGH.................................... 1620
P0071-AMBIENT/BATTERY TEMP SENSOR
PERFORMANCE.......................... 1624
P0107-MAP SENSOR VOLTAGE TOO LOW . 1629
P0108–MAP SENSOR VOLTAGE TOO HIGH . 1634
P0111-INTAKE AIR TEMP PERFORMANCE . . 1639
P0112-INTAKE AIR TEMP SENSOR
VOLTAGE TOO LOW...................... 1643
P0113-INTAKE AIR TEMPERATURE
SENSOR CIRCUIT HIGH.................. 1647
P0117-ENGINE COOLANT TEMPERATURE
SENSOR CIRCUIT LOW................... 1651
P0118-ENGINE COOLANT TEMP SENSOR
VOLTAGE TOO HIGH...................... 1655
P0121-TP SENSOR VOLTAGE DOES NOT
AGREE WITH MAP........................ 1659
P0122-THROTTLE POSITION SENSOR #1
VOLTAGE TOO LOW...................... 1667
P0123-THROTTLE POSITION SENSOR #1
VOLTAGE TOO HIGH...................... 1672
P0125-INSUFFICIENT COOLANT TEMP FOR
CLOSED-LOOP FUEL CONTROL........... 1677
P0131-O2 SENSOR 1/1 CIRCUIT VOLTAGE
TOO LOW................................ 1680
P0132-O2 SENSOR 1/1 CIRCUIT VOLTAGE
TOO HIGH............................... 1683
P0133-O2 SENSOR 1/1 SLOW RESPONSE . 1688
P0135-O2 SENSOR 1/1 HEATER
PERFORMANCE.......................... 1691
P0136-O2 SENSOR 1/2 HEATER CIRCUIT
MALFUNCTION........................... 1694
P0137-O2 SENSOR 1/2 CIRCUIT LOW ..... 1697
P0138-O2 SENSOR 1/2 CIRCUIT HIGH ..... 1701
P0139-O2 SENSOR 1/2 SLOW RESPONSE . 1706
P0141-O2 SENSOR 1/2 HEATER
PERFORMANCE.......................... 1709
P0151-O2 SENSOR 2/1 CIRCUIT LOW ..... 1713
P0152-O2 SENSOR 2/1 CIRCUIT HIGH ..... 1716
P0153-O2 SENSOR 2/1 SLOW RESPONSE . 1721P0155-O2 SENSOR 2/1 HEATER
PERFORMANCE.......................... 1724
P0157-O2 SENSOR 2/2 CIRCUIT VOLTAGE
TOO LOW................................ 1728
P0158-O2 SENSOR 2/2 CIRCUIT VOLTAGE
TOO HIGH............................... 1732
P0159-O2 SENSOR 2/2 SLOW RESPONSE . 1737
P0161-O2 SENSOR 2/2 HEATER
PERFORMANCE.......................... 1740
P0171-FUEL SYSTEM 1/1 LEAN ........... 1744
P0172-FUEL SYSTEM 1/1 RICH ............ 1751
P0174-FUEL SYSTEM 2/1 LEAN ........... 1757
P0175-FUEL SYSTEM 2/1 RICH ............ 1764
P0197-ENGINE OIL TEMPERATURE
SENSOR VOLTAGE TOO LOW............. 1770
P0198-ENGINE OIL TEMPERATURE
SENSOR VOLTAGE TOO HIGH............ 1773
P0201-FUEL INJECTOR 1 CIRCUIT ........ 1777
P0202-FUEL INJECTOR 2 CIRCUIT ........ 1781
P0203-FUEL INJECTOR 3 CIRCUIT ........ 1785
P0204-FUEL INJECTOR 4 CIRCUIT ........ 1789
P0205-FUEL INJECTOR 5 CIRCUIT ........ 1793
P0206-FUEL INJECTOR 6 CIRCUIT ........ 1797
P0207-FUEL INJECTOR 7 CIRCUIT ........ 1801
P0208-FUEL INJECTOR 8 CIRCUIT ........ 1805
P0209-FUEL INJECTOR 9 CIRCUIT ........ 1809
P0210-FUEL INJECTOR 10 CIRCUIT....... 1813
P0300-MULTIPLE CYLINDER MISFIRE ..... 1817
P0301-CYLINDER #1 MISFIRE ............. 1823
P0302-CYLINDER #2 MISFIRE ............. 1832
P0303-CYLINDER #3 MISFIRE ............. 1841
P0304-CYLINDER #4 MISFIRE ............. 1850
P0305-CYLINDER #5 MISFIRE ............. 1859
P0306-CYLINDER #6 MISFIRE ............. 1868
P0307-CYLINDER #7 MISFIRE ............. 1877
P0308-CYLINDER #8 MISFIRE ............. 1886
P0309-CYLINDER #9 MISFIRE ............. 1895
P0310-CYLINDER #10 MISFIRE ............ 1904
P0320–NO CANK REFERENCE SIGNAL AT
PCM..................................... 1913
P0325-KNOCK SENSOR 1 CIRCUIT ........ 1921
P0330-KNOCK SENSOR 2 CIRCUIT ........ 1925
P0340-CAMSHAFT POSITION SENSOR
CIRCUIT................................. 1929
P0352-IGNITION COIL #2 PRIMARY
CIRCUIT................................. 1936
P0353-IGNITION COIL #3 PRIMARY
CIRCUIT................................. 1940
P0354-IGNITION COIL #4 PRIMARY
CIRCUIT................................. 1944

When Monitored:
With the ignition on and no Battery Temperature Sensor Open or Short Faultspresent.
Set Condition:
After 5 warm cycles have occurred (coolant increases at least 22°C (40°F) to a minimum of 71°C (160°F) and
the odometer mileage has increased 196.6 miles and the Battery Temperature has changed less than 4°C
(7.2°F) change in temperature. One trip fault.
Possible Causes
GOOD TRIP EQUAL TO ZERO
(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
BATTERY TEMPERATURE SENSOR
RESISTANCE IN THE (K25) BATTERY TEMP SENSOR SIGNAL CIRCUIT
RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
(K25) BATTERY TEMP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Symptom. (Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING)
2.(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Battery Temp Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (K25) Battery Temp Signal circuit at the
Sensor connector.
Is the voltage above 5.2 volts?
Ye s>>
Repair the short to voltage on the (K25) Batt Temp Signal
circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 3

When Monitored:
With the ignition on and no Intake Air Temperature Sensor open/shorted faults present.
Set Condition:
After 5 warm cycles have occurred (coolant increases at least 22°C (40°F) to a minimum of 71°C (160°F) and
the odometer mileage has increased 196.6 miles and the Intake Air Temperature has had less than 5°C (9°F)
change in temperature.
Possible Causes
RESISTANCE IN THE (K21) IAT SENSOR SIGNAL CIRCUIT
RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
IAT SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
2.IAT SENSOR VOLTAGE ABOVE 4.6 VOLTS
Turn the ignition off.
Disconnect the Intake Air Temperature Sensor harness connector.
Ignition on, engine not running.
With the scan tool, read the IAT voltage.
Is the voltage above 4.6 volts?
Ye s>>
Go To 3
No>>
Go To 5

P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W.