RCT Sensor

The engine coolant temperature (ECT) 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:

P00B3

P00B4

P00B3 00

The ECM detects that the engine coolant temperature (ECT) sensor 2 is greater than 149°C (300°F) for greater than 5 s.

P00B4 00

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.

DTCs P00B3 00 and P00B4 00 are Type B DTCs.

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.

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

Note: The intake air temperature must be between -7 to +70°C (19 to 158°F) for the DTCs to set.

1. Engine idling, observe the DTC information with a scan tool. DTC P00B3 00 or P00B4 00 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.

1. Ignition OFF, disconnect the harness connector at the B34B Engine Coolant Temperature (ECT) Sensor 2.
2. Ignition OFF for 1 m, test for less than 5 Ω between the ground circuit terminal 1 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 (ECM).

3. Ignition ON, verify the scan tool ECT Sensor 2 sensor parameter is at -40°C (-40°F).

⇒	If greater than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

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 1 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the ECT Sensor 2 sensor parameter is at 150°C (302°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 (ECM).

5. If all circuits test normal, test or replace the B34B Engine Coolant Temperature (ECT) Sensor 2.

Static Test

1. Ignition OFF, disconnect the harness connector at the B34B Engine Coolant Temperature (ECT) Sensor 2.

Note: A thermometer can be used to test the sensor off the vehicle.

2. Test the B34B Engine Coolant Temperature (ECT) Sensor 2 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the LINK (Temperature Versus Resistance) table and verify that the resistance is within 5% of the specification.

⇒	If not within the specified range, replace the B34B Engine Coolant Temperature (ECT) Sensor 2.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.