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Home >> Lexus >> 2025 >> NX 350h >> Repair and Diagnosis >> External Pages >> Different car >> Section 64 (Stop And Start System - Diagnostic Codes (1 Of 2)) >> Stop And Start System >> DTC P1644-00: ECU Malfunction (Starter Circuit) [11/2021 - 03/2023] >> Description

DTC P1644-00: ECU Malfunction (Starter Circuit) [11/2021 - 03/2023]: Description

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If a malfunction is detected in the starter circuit, the engine stop and start ECU stores DTC P1644-00 and blinks the stop and start cancel indicator.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Note
P1644-00 ECU Malfunction (Starter Circuit) Both of the following conditions are met for 0.2 seconds or more (1 trip detection logic):
  • Ignition switch ON
  • Malfunction in starter circuit (STA)
  • Wire harness or connector
  • ST NO. 1 relay
  • Engine stop and start ECU
Blinks SAE Code: P1644