DTC P0117 or P0118 (LUJ)
Diagnostic Instructions
DTC Descriptors
| DTC P0117 00: Engine Coolant Temperature (ECT)
Sensor Circuit Low Voltage |
| DTC P0118 00: Engine Coolant Temperature (ECT)
Sensor Circuit High Voltage |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
ECT Sensor Signal
|
P0117 00
|
P0118 00
|
P0118 00*
|
-
|
Low Reference
|
-
|
P0118 00
|
P0118 00*
|
-
|
* Internal ECM or sensor damage may occur if the circuit is
shorted to B+.
|
|
| |
Typical Scan Tool Data
ECT Sensor
Circuit
|
Short to Ground
|
Open
|
Short to Voltage
|
Operating Conditions: Engine operating
in closed loop
Parameter Normal Range: Varies with
ambient air temperature, within a range of -39 to +120°C (-38
to +248°F)
|
ECT Sensor Signal
|
150°C (302°F)
|
-40°C (-40°F)
|
-40°C (-40°F)*
|
Low Reference
|
-
|
-40°C (-40°F)
|
-40°C (-40°F)*
|
*Internal ECM or sensor damage may occur if the circuit is shorted
to B+.
|
|
| |
Circuit/System Description
The engine coolant temperature (ECT) sensor 1 is a variable
resistor that measures the temperature of the engine coolant. The
engine control module (ECM) supplies 5 V to the engine coolant
temperature (ECT) sensor 1 signal circuit and a ground for the low
reference circuit.
The following table illustrates the difference between
temperature, resistance, and voltage:
ECT
|
ECT Resistance
|
ECT Signal Voltage
|
Cold
|
High
|
High
|
Warm
|
Low
|
Low
|
|
| |
Conditions for Running the DTC
P0117 00
| • |
The ignition is ON, or the
engine is running. |
| • |
The battery voltage is greater
than 9 V. |
| • |
The DTC runs continuously when
the above conditions are met. |
P0118 00
| • |
The engine run time is greater
than 60 s. |
| • |
The intake air temperature
(IAT) sensor is greater than 0°C (32°F). |
| • |
The DTC runs continuously when
the above conditions are met. |
Conditions for Setting the DTC
P0117 00
The ECM detects that the engine coolant temperature (ECT) sensor 1
signal is less than 0.27 V, which is warmer than 137°C
(279°F) for greater than 2 s.
P0118 00
The ECM detects that the engine coolant temperature (ECT) sensor 1
signal is greater than 4.96 V, which is colder than -39°C
(-38°F) for greater than 2 s.
Action Taken When the DTC Sets
| • |
DTCs P0117 00, and P0118 00
are Type B DTCs. |
| • |
The cooling fans will be
commanded ON. |
| • |
The A/C compressor will be
commanded OFF. |
Conditions for Clearing the DTC
DTCs P0117 00, and P0118 00 are Type B DTCs.
Diagnostic Aids
Note: The engine coolant
temperature (ECT) sensor 1 is mounted on the engine and the engine
coolant temperature (ECT) sensor 2, radiator coolant temperature
(RCT) sensor, is mounted on the radiator.
| • |
The engine coolant temperature
gauge will display full cold when an ECT DTC sets. |
| • |
After starting the engine, the
engine coolant temperature (ECT) sensor 1 temperature should rise
steadily, then stabilize after the thermostat opens. |
| • |
Test the engine coolant
temperature (ECT) sensor 1 at various temperature levels in order
to evaluate the possibility of a skewed sensor. A skewed sensor can
result in a driveability condition. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. |
If the ignition has been OFF
for 8 h or greater, the intake air temperature, ambient air
temperature, and the engine coolant temperature (ECT) sensor 1
should be within 9°C (16°F) of each other. Ignition ON,
observe the scan tool IAT Sensor, Ambient Air Temperature, and the
ECT Sensor 1 parameters. Compare those sensor parameters to each
other to determine if the condition is current. |
| 2. |
Engine running, observe the
ECT Sensor 1 parameter. The reading should be between -39 to
+120°C (-38 to +248°F) depending on the current ambient air
temperature, the engine run time, and the vehicle operating
conditions. |
| 3. |
Operate the vehicle within the
conditions for running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
harness connector at the B34A Engine Coolant Temperature Sensor
1. |
| 2. |
Ignition OFF, test for less
than 5 Ω between the low reference circuit terminal 2 and
earth. |
| ⇒ |
If greater than the specified range, test the low
reference circuit for an open/high resistance. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 3. |
Ignition ON, verify the scan
tool ECT Sensor 1 is at -40°C (-40°F). |
| ⇒ |
If warmer than the specified value, test the
signal circuit terminal 1 for a short to ground. If the circuit
tests normal, replace the K20 Engine Control Module. |
|
Note: If the fuse in
the jumper wire opens, the signal circuit is shorted to a voltage
and the sensor may be damaged.
|
| 4. |
Install a 3 A fused jumper
wire between the engine coolant temperature (ECT) sensor 1 signal
circuit terminal 1 and ground. Verify the scan tool ECT Sensor 1 is
greater than 130°C (266°F). |
| ⇒ |
If less than the specified range, test the signal
circuit for a short to voltage or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| 5. |
If all circuits test normal,
test or replace the B34A Engine Coolant Temperature Sensor
1. |
Component Testing
Static Test
| 1. |
Ignition OFF, disconnect the
harness connector at the B34A Engine Coolant Temperature Sensor
1. |
| 2. |
Test the B34A Engine Coolant
Temperature Sensor 1 by varying the sensor temperature while
monitoring the sensor resistance. Compare the readings with the
Temperature Versus Resistance table and verify that the
resistance is within 5% of the specification. |
| ⇒ |
If not within the specified range, replace the
B34A Engine Coolant Temperature Sensor 1. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
