P00B6
DTC P00B6
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P00B6
- Radiator Coolant Temperature (RCT) - Engine Coolant Temperature (ECT) Correlation
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The radiator coolant temperature (RCT) sensor is a variable resistor that measures the temperature of the radiator coolant. The ECM supplies 5 V to the RCT sensor signal circuit and supplies a ground for the low reference circuit.
The following table illustrates the difference between temperature, resistance, and voltage:
Conditions for Running the DTC
* DTCs P00B3, P00B4, P0112, P0113, P0117, P0118 or P2610 are not set.
* The ignition has been off for greater than 8 h before vehicle is started.
* The ignition is ON, or the engine is running.
* The intake air temperature (IAT) is greater than -7°C (19°F).
* The fuel level is greater than 10%.
* The DTC runs once per ignition cycle when the above conditions are met.
Conditions for Setting the DTC
This DTC sets if one of the following conditions occurs for less than 1 s:
* The ECM detects the RCT sensor and the ECT sensor are greater than a predetermined intake air temperature at engine start-up.
* The ECM detects the RCT sensor is 20°C (68°F) warmer than the ECT sensor at engine start-up and the block heater has not been detected.
* The ECM detects the RCT sensor is 20°C (68°F) warmer than the ECT sensor at engine start-up and the engine has been cranking for greater than 10 s without a fuel level sensor DTC.
Action Taken When the DTC Sets
DTC P00B6 is a Type B DTC.
Conditions for Clearing the DTC
DTC P00B6 is a Type B DTC.
Diagnostic Aids
* If the vehicle has sat overnight, the RCT sensor and the ECT sensor values should display within 3°C (5°F).
* As the thermostat opens, the RCT sensor temperature should rise steadily, then stabilize once the thermostat opens completely.
* Test the RCT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor.
* Inspect for the correct operation of the engine cooling system and verify the correct coolant level.
* If the condition is intermittent, allowing the vehicle to sit for greater than 8 h with the ignition OFF, may help isolate the condition. Compare the scan tool RCT and ECT temperature sensor values at Ignition ON. The RCT sensor and the ECT sensor values should display within 3°C (5°F).
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Cooling System Description and Operation (Cooling System)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. DTC P00B3, P00B4, P0117, or P0118 should not be set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.
2. Verify the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks.
3. Engine idling for 15 min with the A/C OFF.
Note: Depending on ambient temperature, it may take up to 4 min for the temperatures to equalize.
4. Increase the engine speed to 3 000 RPM. Observe the scan tool RCT and the ECT sensor parameters. The RCT and the ECT sensor parameters should be within 20°C (68°F).
5. 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 B34B Engine Coolant Temperature Sensor 2.
2. Ignition OFF, test for less than 5 ohm 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 B34B Engine Coolant Temperature Sensor 2 parameter is -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 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 1 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool B34B Engine Coolant Temperature Sensor 2 parameter is at 150°C (302°F).
• If less than 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 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 the 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 table and verify that the resistance 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 Sensor 2.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for ECM replacement, setup and programming