OBD Guide

P1A9D

Starter/Generator Inverter Phase U Temperature Sensor Circuit High Voltage

P1A9D is an OBD-II diagnostic trouble code meaning: Starter/Generator Inverter Phase U Temperature Sensor Circuit High Voltage. Common causes: phase u temperature sensor fault, damage to wires or connectors in the sensor circuit. Estimated repair cost: $56–167.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–167 (est.)

Symptoms

  • The malfunction indicator light comes on
  • Problems starting the engine
  • Unstable generator operation
  • Hybrid system power reduction
  • The car goes into emergency mode

Causes

  • Phase U temperature sensor fault
  • Damage to wires or connectors in the sensor circuit
  • Starter/Generator Inverter Problems
  • Short circuit in the circuit
  • Malfunction of the hybrid system control unit

How to Fix

  1. Check the integrity of the wiring to the temperature sensor
  2. Check connectors for corrosion or damage
  3. Measure the resistance of the temperature sensor
  4. Check the voltage in the sensor circuit
  5. If necessary, replace the phase U temperature sensor
  6. Repair only from an authorized dealer

Related codes

FAQ

What does the P1A9D code mean?

P1A9D is an OBD-II diagnostic trouble code that indicates: Starter/Generator Inverter Phase U Temperature Sensor Circuit High Voltage

What causes a P1A9D error code?

The most common causes of P1A9D include: Phase U temperature sensor fault; Damage to wires or connectors in the sensor circuit; Starter/Generator Inverter Problems; Short circuit in the circuit.

How do I fix a P1A9D diagnostic trouble code?

To fix P1A9D: Check the integrity of the wiring to the temperature sensor. Check connectors for corrosion or damage. Measure the resistance of the temperature sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1A9D?

Do not drive — repair immediately

How much does it cost to fix P1A9D?

The estimated repair cost for P1A9D is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat