OBD Guide

P1621

Control Module Long Term Memory Performance Condition

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Unstable engine operation
  • Increased fuel consumption
  • Check Engine Light Illuminates
  • Losing saved settings (for example, radio stations)
  • Problems starting the engine

Causes

  • Engine control unit malfunction
  • ECU power problems
  • Short circuit in ECU circuit
  • Corrosion of control unit contacts
  • Software error in ECU

How to Fix

  1. Check the supply voltage of the control unit
  2. Inspect ECU connectors and wiring harness
  3. Check for corrosion on contacts
  4. Flash or replace the control unit
  5. Reset the error and check for its reappearance

Related codes

Error P1621 by Vehicle Brand