A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- High-voltage system insulation fault
- Damaged high-voltage cable or connector
- Water or electrolyte in the high-voltage parts
What you can do yourself
- Danger: high voltage may leak to the body. Don’t touch the orange cables and don’t pressure-wash the engine bay.
- Don’t drive — call a mechanic or a tow truck.
- High-voltage repairs are for a hybrid specialist only.
OOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
As given in the Prius 2001–2003 repair manual. This is the Toyota and Lexus meaning. On other makes this number means something else: if your car isn’t a Toyota or Lexus, change the make at the top.
Source: prius.ecrostech.com, obdadvisor.com
The explanation comes from the error code reference in the AvtoElektrik PRO app.