OBD Guide

P1647

HO2 Sensor Control Malfunction Bank 2 Upstream

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Check Engine light comes on
  • Increased fuel consumption
  • Unstable engine operation at idle
  • Reduced engine power
  • Increase in harmful emissions

Causes

  • Bank 2 oxygen sensor malfunction
  • Open or short circuit in the sensor circuit
  • Poor contact in the sensor connector
  • Engine control module (ECU) malfunction
  • Problems with sensor ground

How to Fix

  1. Check the condition and connection of the oxygen sensor
  2. Check the integrity of wires and connectors in the sensor circuit
  3. Measure the resistance of the sensor heating element
  4. Check sensor signals with an oscilloscope
  5. If necessary, replace the oxygen sensor

Related codes

Error P1647 by Vehicle Brand