P0A73 code meaning
Generator Phase V Current Low
Powertrain system Generic code P0Axx codes Check engine light
What P0A73 means
P0A73 indicates that phase V of the hybrid generator delivers or reports too little current under load. No manufacturer documents P0A73 publicly. On inverters that measure only phases V and W, a low V reading has a knock-on effect: the calculated U current is wrong as well, so the generator torque control loses accuracy. A Caterpillar patent shows the logic for three-sensor systems, where a near-zero reading plus a violated zero-sum identifies the failed sensor; a Toyota patent compares a control sensor with a monitoring sensor and the current command. CARB requires circuit monitoring of electric drive components. P0A74 is the high side, P0A70 and P0A76 phases U and W, P0A72 the general code. Charging and engine start can suffer.
P0A73 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1.5 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0A73
- Hybrid warning and MIL
- Engine runs more often, battery charge does not recover
Common causes of P0A73
- Most likelyGenerator phase V current sensor reading near zero
- PossibleGenerator phase V lead or terminal open
- Less likelyPhase V switch in the generator inverter not conducting
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Generator phase vInverter
What each part of P0A73 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 73 | The exact fault in that area. |
What to do next
- Note P0A73 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0A73
What does P0A73 mean?
P0A73 means "Generator Phase V Current Low". P0A73 indicates that phase V of the hybrid generator delivers or reports too little current under load. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A73?
Drive gently and only to a workshop. With P0A73 the car can go into limp mode (reduced power) to protect itself.
Will P0A73 fail an emissions test?
Yes, it can. P0A73 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0A73 to fix?
Difficulty: workshop only. A typical repair takes 1.5 to 8 hours of work. This is a job for a workshop.
Will P0A73 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.