DTC P00B3 or P00B4
Diagnostic Instructions
DTC Descriptors
| DTC P00B3: Radiator Coolant Temperature (RCT)
Sensor Circuit Low Voltage |
| DTC P00B4: Radiator Coolant Temperature (RCT)
Sensor Circuit High Voltage |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
RCT Signal Circuit
|
P0033
|
P00B4
|
P00B4*
|
P00B6
|
Low Reference
|
-
|
P00B4
|
P00B4*
|
P00B6
|
* Internal ECM or sensor damage may occur if the circuit is
shorted to B+.
|
|
| |
Typical Scan Tool Data
Radiator Coolant Temperature Sensor
Circuit
|
Short to Ground
|
Open
|
Short to Voltage
|
Operating Conditions: The ignition is
ON, or the engine is running.
Parameter Normal Range: Varies with
ambient temperature.
|
RCT 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 2 (Radiator Coolant
Temperature (RCT) Sensor 2) is a variable resistor that measures
the temperature of the engine coolant in the radiator. The engine
control module (ECM) supplies 5 V to the engine coolant temperature
(ECT) sensor 2 signal circuit and supplies a ground to the low
reference circuit.
The following table illustrates the difference between
temperature, resistance, and voltage:
RCT
|
RCT Resistance
|
RCT Signal Voltage
|
Cold
|
Warm
|
High
|
Warm
|
Low
|
Low
|
|
| |
Conditions for Running the DTC
P00B3
| • |
DTCs P0112 or P0113 are not
set. |
| • |
The engine run time is greater
than 10 s. |
| • |
The intake air temperature
(IAT) is less than 70°C (158°F). |
| • |
The DTCs run continuously when
the above conditions are met. |
P00B4
| • |
DTCs P0112 or P0113 are not
set. |
| • |
The engine run time is greater
than 60 s. |
| • |
The intake air temperature
(IAT) is less than -7°C (19°F). |
| • |
The DTCs run continuously when
the above conditions are met. |
Conditions for Setting the DTC
P00B3
The ECM detects that the engine coolant temperature (ECT) sensor 2
is greater than 149°C (300°F) for greater than 5 s.
P00B4
Note: The scan tool
only displays to -40°C (-40°F).
The ECM detects that the engine coolant temperature
(ECT) sensor 2 is colder than -60°C (-76°F) for greater
than 5 s.
Action Taken When the DTC Sets
| • |
DTCs P00B3 and P00B4 are Type
B DTCs. |
| • |
The cooling fans will be
commanded ON by the ECM. |
Conditions for Clearing the DTC
DTCs P00B3 and P00B4 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.
| • |
As the thermostat opens, the
engine coolant temperature (ECT) sensor 2 temperature should rise
steadily, then stabilize once the thermostat opens
completely. |
| • |
Test the engine coolant
temperature (ECT) sensor 2 at various temperature levels in order
to evaluate the possibility of a skewed sensor. |
| • |
If the vehicle has sat
overnight, the engine coolant temperature (ECT) sensor 2 and the
engine coolant temperature (ECT) sensor 1 values should display
within 3°C (5°F). |
Reference Information
Schematic Reference
Connector End View Reference
Component Connector End Views
Description and Operation
Cooling System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Note: The intake air
temperature must be between -7 to +70°C (19-158°F) for the
DTCs to set.
| 1. |
Engine idling, observe the DTC
information with a scan tool. DTC P00B3 or P00B4 should not
set. |
| 2. |
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 B34B Engine Coolant Temperature Sensor
2. |
| 2. |
Ignition OFF for 1 min, test
for less than 5 Ω between the low reference circuit terminal
2 and ground. |
| ⇒ |
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 Radiator Coolant Temperature Sensor parameter is at -40°C
(-40°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. |
|
Caution: If
the fuse in the jumper wire opens, the signal circuit may have a
short to a voltage or a short to ground and the sensor might be
damaged. |
| 4. |
Install a 1 A fused jumper
wire between the signal circuit terminal 1 and the low reference
circuit terminal 2. Verify the Radiator Coolant Temperature Sensor
parameter is at 140°C (284°F). |
| ⇒ |
If less than the specified value, 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 B34B Engine Coolant Temperature Sensor
2. |
Component Testing
Static Test
| 1. |
Ignition OFF, disconnect the
harness connector at the B34B Engine Coolant Temperature Sensor
2. |
|
Note: A thermometer
can be used to test the sensor off the vehicle.
|
| 2. |
Test the B34B Engine Coolant
Temperature Sensor 2 by varying the sensor temperature while
monitoring the sensor resistance. Compare the readings with the
Temperature Versus Resistance . |
| ⇒ |
If not within the specified range, replace the
B34B Engine Coolant Temperature Sensor 2. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
