Cause
High voltage cover or connector not latched
A high-voltage cover, service plug or connector has not been fully closed and latched, so the interlock circuit that runs through it is open.
The interlock is a thin wire threaded through every orange cover and every high-voltage plug on the vehicle, in series. Its whole purpose is to be broken before anything live can be touched: open the loop anywhere and the car refuses to close its contactors, so the system de-energises before a hand reaches it. That design makes this cause both very common and, usually, very cheap.
It is overwhelmingly a consequence of work rather than of age, and the vehicle's history tells you so. A pack inspection, a coolant repair, an inverter or charger job, bodywork near the battery, even a thorough inspection — anything that involved lifting a cover puts this on the list. Connectors of this kind deliberately have a two-stage action, seating first and latching second, so one that looks and feels fitted can be a single movement short, and that is precisely the state that produces the code.
The practical consequence is that a car which will not power on straight after high-voltage work is very often this, and the fix is free. Saying so when booking it in can turn a recovery into a two-minute job.
And the rule that goes with it has no exceptions: the loop is never bridged. Jumping an interlock to get a vehicle moving removes the guarantee that the pack can be de-energised, and the next person to work on it — perhaps at a roadside, perhaps after a collision — will be trusting a safety system that is no longer there.
Typically specialist work. Needs equipment or training most home workshops do not have.
Some of these codes mean you should stop driving
8 of the 13 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (13)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0A0A High Voltage System Interlock Circuit A Likely for this code Stop driving Critical
- P0A0B High Voltage System Interlock Circuit A Performance Likely for this code Stop driving Critical
- P0A0D High Voltage System Interlock Circuit A High Likely for this code Stop driving Critical
- P0A0E High Voltage System Interlock Circuit A Intermittent Likely for this code Stop driving Critical
- P0B37 High Voltage Service Disconnect Open Likely for this code Stop driving High
- P0D15 Battery Charging System A High Voltage Interlock Circuit/Open Likely for this code High
- P0D16 Battery Charging System A High Voltage Interlock Circuit Performance Likely for this code Moderate
- P0D17 Battery Charging System A High Voltage Interlock Circuit Low Likely for this code Moderate
- P0D18 Battery Charging System A High Voltage Interlock Circuit High Likely for this code Moderate
- P0D19 Battery Charging System A High Voltage Interlock Circuit Intermittent/Erratic Likely for this code Moderate
- P0B33 High Voltage Service Disconnect Circuit Stop driving High
- P0B34 High Voltage Service Disconnect Circuit Performance Stop driving High
- P0B36 High Voltage Service Disconnect Circuit High Stop driving High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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