P00B7 - ENGINE COOLANT FLOW LOW / PERFORMANCE

The engine coolant temperature sensor (ECT) is usually made of a thermal resistor, which is covered by a resin and finally sealed by a metal or plastic housing. This sensor may be located near the thermostat or in the coolant passages around the intake manifold.

The thermal resistance of the Engine Coolant Temperature is low as the coolant heats up and passes through the system components. As a result, the voltage will increase in the ECT sensor circuit to the PCM.

When the Powertrain Control Module detects some out-of-range voltage levels at the Engine Coolant Temperature, which indicates low performance, the diagnostic code P00B7 OBDII will be set.

• Check Engine light ON.
• High radiator fan speed.
• Inconveniences in driving the vehicle.
• Poor fuel economy performance.

The reasons for storing the DTC P00B7 OBD2 code are:

• The amount of coolant in the engine may not be right.
• Wires or connectors associated with the Coolant Temperature Sensor circuit may have some damage, causing an open circuit.
• The thermostat may be faulty.
• The ECT sensor may be in bad condition.

To troubleshoot the P00B7 OBDII fault code, try this :

• Consult the Technical Service Bulletin (TSB).
• Check if the engine coolant level is adequate. If you find that level that does not meet the requirements for good system performance, make sure it is not due to leaks. Make the appropriate repairs.
• Check the wiring and connectors related to the ECT Sensor circuit are not damaged. Repair or replace if necessary.
• Use a DVOM and check the reference voltage and grounding of the ECT Sensor. If the reading obtained reflects inconsistency compared to the values specified by the manufacturer, check the wiring of the ECT sensor and, if necessary, replace the Coolant Temperature Sensor.