P0E79
Coolant Bypass Valve B Control Circuit High
The coolant bypass valve B reports a control circuit high condition. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
The coolant bypass valve B reports a control circuit high condition. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Common causes
- high
Wire shorted to B+
One of the most commonly reported causes for this code — check this first.
Typical part cost: $220-1320
- medium
Coil open
A plausible cause — test and verify before replacing parts.
Typical part cost: $220-1320
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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
See related trouble codes
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Frequently asked questions
What does P0E79 mean?
P0E79 means "Coolant Bypass Valve B Control Circuit High". It is a generic OBD-II code that points to a fault in the hybrid / ev powertrain.
What are the most common causes of P0E79?
wire shorted to b+; coil open; 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?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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