Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected a problem with the electrical circuit that controls the heater for the engine coolant. It's like when a light switch in your house isn't working because the wires are not connected properly.
The P2B73 code is triggered when the Engine Control Module (ECM) detects a low voltage condition in the control circuit of the coolant heater A.
The coolant heater is responsible for warming up the engine coolant to help the engine reach its optimal operating temperature more quickly. The control circuit for this heater is monitored by the ECM. If the voltage in the circuit is lower than expected, the ECM will set the P2B73 code.
• Check Engine Light illuminated
• Engine takes longer to reach operating temperature
• Poor heater performance in cold weather
• Faulty coolant heater
• Open or shorted wiring in the coolant heater circuit
• Poor electrical connection in the coolant heater circuit
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors in the coolant heater circuit for damage.
• Test the coolant heater for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty coolant heater.
• Clear the code and test drive the vehicle to ensure the issue is resolved.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Toyota Camry
• Ford F-150
• Chevrolet Silverado
• Regularly inspect and maintain electrical connections.
• Ensure proper coolant levels and quality.
• Schedule routine vehicle maintenance.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving in extreme cold until the issue is fixed.
Check with the vehicle manufacturer for specific warranty details related to the coolant heater system.
The P2B73 code has been associated with vehicles that have complex heating systems, especially in colder climates.
Moderate – While the vehicle can still be driven, it is advisable to address the issue to prevent further complications.
Driving with a malfunctioning coolant heater can lead to increased emissions and may affect vehicle performance in cold weather.
• Vehicle at operating temperature
• Ambient temperature below 50°F
The coolant heater is typically located near the engine block, integrated into the cooling system.
Q: Can I drive with a P2B73 code?
A: Yes, but it's best to get it fixed soon to avoid potential engine performance issues.
Q: How do I clear a P2B73 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is resolved, the code should not return.
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