P0A0C

  • Powertrain
  • Generic (SAE)
  • Safety
SeveritySeverity level 5 of 5: Stop driving.

Stop driving

Continuing to drive risks injury or major mechanical damage. Shut the engine off when it is safe to do so.

Standard definition

High Voltage System Interlock Circuit Low

This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.

In plain English

The HV interlock signal is below threshold, indicating broken loop or short to ground. 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.

A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.

Can I keep driving?
Safe to drive
Continuing to drive risks injury or major mechanical damage. Shut the engine off when it is safe to do so.
Urgency
Stop driving
Will it pass emissions
Not affected
Check engine light
Solid
Likely causes
#CauseHow oftenComponent
1Interlock loop brokenVery common
2Connector pins corroded - high contact resistanceOccasional
3Harness chafing through insulationOccasional

Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.

Components involved
  • HV Interlock Loop
  • HV Service Connector
Sources
Definition
Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
Diagnostic guidance
Written and reviewed in-house. See our editorial policy.
Review status
Awaiting review

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