P2B73

Coolant Heater A Control Circuit Low

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–89 (est.)

Symptoms

Extended engine warm-up time
Unstable engine operation in the cold
Check Engine Light Illuminates
Reduced interior heating efficiency
Possible problems with starting in cold weather

Causes

Coolant heater malfunction
Open or short circuit in control circuit
Poor contact in connectors
Heater relay malfunction
Problems with the engine control unit

How to Fix

Check the integrity of the heater control circuit
Check the condition of connectors and contacts
Check the functionality of the coolant heater
Check heater relay
If necessary, replace faulty components

Related codes

P2B74 P2B72 P2B75