DTC P0116 (LUJ)
Diagnostic Instructions
DTC Descriptor
| DTC P0116 00: Engine Coolant Temperature (ECT)
Sensor Performance |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Signal Circuit
|
P0117 00
|
P0118 00
|
P0118 00*
|
P0116 00
|
Low Reference
|
-
|
P0118 00
|
P0118 00*
|
P0116 00
|
*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
coolant temperature
|
Signal
|
150°C (302°F)
|
-40°C (-40°F)
|
-40°C (-40°F)
|
Low Reference
|
-
|
-40°C (-40°F)
|
-40°C (-40°F)
|
|
| |
Circuit/System Description
The engine coolant temperature (ECT) sensor is a variable
resistor that measures the temperature of the engine coolant. The
engine control module (ECM) supplies 5 V to the ECT sensor signal
circuit and a ground for the low reference circuit.
The purpose of this diagnostic is to determine if the input from
the ECT sensor is skewed warmer than normal. The internal clock of
the ECM will record the amount of time the engine is OFF. If the
required engine OFF time is met at start-up, the ECM will compare
the temperature difference between the actual measured ECT and a
calibrated ECT model. The information for this model is derived
from the previous drive cycle and includes the accumulated mass air
flow (MAF), the engine run time, the ambient air temperature and
the ECT at the end of the drive cycle.
If the ECM detects that the temperature difference between the
measured and modeled ECT is not within an acceptable operating
range of each other, then the ECM will continue to run this
diagnostic to determine if a block heater was active during the
engine OFF time.
Conditions for Running the DTC
| • |
DTCs P0112 00, P0113 00, P0117
00, P0118 00, and P2610 00 are not set. |
| • |
The ignition has been off for
greater than 8 h before the engine is started. |
| • |
This DTC runs once per
ignition cycle when the above conditions are met. |
Conditions for Setting the DTC
The ECM does not detect an ECT sensor change of greater than
10.5°C (50.9°F) within a calibrated time.
Action Taken When the DTC Sets
DTC P0116 00 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0116 00 is a Type B DTC.
Diagnostic Aids
| • |
Inspect the ECT sensor
terminals for corrosion and for engine coolant leaking through the
sensor. Engine coolant that is leaking through the sensor will
create a high resistance short to ground. This condition results in
less voltage on the ECT sensor signal circuit, which is interpreted
by the ECM as a warmer ECT. |
| • |
An intake air temperature
(IAT) sensor that is biased colder at various ambient temperatures
due to greater resistance than is normal will increase the range
between these 2 sensors. Measure and record the resistance of the
IAT sensor at various ambient temperatures, then compare those
measurements to the Temperature vs. Resistance table. Refer to
Temperature Versus Resistance . |
| • |
Test the ECT sensor at various
temperature levels in order to evaluate the possibility of a biased
sensor. A sensor that is biased warmer can result in a driveability
condition. Refer to
Temperature Versus Resistance . |
| • |
A slight to moderate
resistance in the IAT sensor signal circuit or low reference
circuit will increase the range between these two sensors. This
condition results in a greater voltage on the IAT sensor signal
circuit, which is interpreted by the ECM as a colder IAT.
|
| • |
If the condition is
intermittent, allow the vehicle to sit for greater then 8 h with
the ignition off, may help isolate the condition. Compare the scan
tool Radiator Coolant Temperature Sensor and ECT Sensor temperature
sensor values at ignition on. The Radiator Coolant Temperature
Sensor and the ECT Sensor values should display within 3°C
(5°F). |
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. |
Ignition on, observe the DTC
information with a scan tool. Verify that DTC P0112 00, P0113 00,
P0117 00, or P0118 00 are not set. |
| 3. |
If the ignition has been OFF
for 8 h or greater, the B75B Mass Air Flow/Intake Air Temperature
Sensor (IAT 1), the B111 Turbocharger Boost Sensor (IAT 2), and the
B34A Engine Coolant Temperature Sensor 1 should be within 9°C
(16°F) of each other and also the ambient temperature. Ignition
ON, observe the scan tool IAT Sensor, IAT Sensor 2 and the ECT
Sensor parameters. Compare those sensor parameters to each other
and also to the ambient temperature to determine if the ECT sensor
is skewed. |
|
Note: Depending on
ambient temperature, it may take up to 4 min for the temperature to
equalize.
|
| 4. |
Engine running, observe the
ECT Sensor parameter. The reading should be between -39 to
+120°C (-38 to +248°F) depending on the current ambient
temperature and the vehicle operating conditions. |
| 5. |
Operate the vehicle within the
conditions for running the DTC. 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. |
Inspect the B34A Engine
Coolant Temperature Sensor 1 terminals for corrosion and for engine
coolant leaking through the sensor. |
| 3. |
Ignition OFF for 1 min, 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. |
| 4. |
Ignition ON, verify the scan
tool ECT Sensor parameter is colder than -39°C
(-38°F). |
| ⇒ |
If greater than the specified range, test the
signal circuit terminal 1 for a short to ground. If the circuit
tests normal, replace the K20 Engine Control Module. |
| 5. |
Install a 3 A fused jumper
wire between the signal circuit terminal 1 and the low reference
circuit terminal 2. Verify the scan tool ECT Sensor parameter 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. |
| 6. |
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. |
|
Note: A thermometer
can be used to test the sensor off vehicle.
|
| 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.
|
