P26D4
Engine Coolant Pump Supply Voltage Circuit Low
What it means
The dedicated supply voltage to the coolant pump module is below operating range. 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.
Is it safe to drive?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
High-resistance battery feed
highOne of the most commonly reported causes for this code — check this first.
Weak battery sags under pump current
mediumA plausible cause — test and verify before replacing parts.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Related help
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