P2B73

Coolant Heater A Control Circuit Low

Moderate severity

The control circuit of coolant heater A reports a control circuit low condition. Auxiliary preheating of the coolant cannot be commanded as expected.

Common causes

Control wire shorted to ground
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $130-660
Heater element shorted
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $130-660
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P2B73 mean?

P2B73 means "Coolant Heater A Control Circuit Low". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P2B73?

control wire shorted to ground; heater element shorted; connector pins corroded - high contact resistance — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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