P1602 – Battery Terminal Disconnection (Toyota)

Description

The ECM detected an abnormal battery terminal disconnection event affecting power delivery and system memory.

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Symptoms

  • Hard starting
  • Loss of radio presets
  • ECM resets
  • Intermittent stalling
  • Warning lights on

Causes

  • Loose battery terminals
  • Corroded terminals
  • Weak battery
  • Damaged battery cables
  • Poor ground connection

Diagnosis

  • Inspect terminals
  • Check cable integrity
  • Measure battery voltage
  • Check ground points
  • Scan for related codes

Repair

  • Tighten terminals
  • Clean corrosion
  • Replace battery
  • Repair or replace cables

Related Problems

Related Fault Codes