LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Kia >> 2021 >> Niro Plug-In Hybrid LXS >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System Diagnosis (PHEV) (5 Of 6) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> Wiring Inspection >> Circuit Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit Inspection

G13355372Courtesy of KIA MOTORS AMERICA, INC.
Inspection Condition (+) Probe (-) Probe Specification
Connector Terminal Connector Terminal
  1. Ignition "OFF".
  2. Disconnect the electrical connector(s) from the concerned component.
  3. Ignition "ON".
HO2S (bank1, sensor1) connector 2 (nernst voltage) Chassis ground - Approx. 0V
HO2S (bank1, sensor1) connector 1 (virtual ground) Chassis ground - Approx. 0V
HO2S (bank1, sensor1) connector 6 (trim resistor) Chassis ground - Approx. 0V
HO2S (bank1, sensor1) connector 3 (pumping line) Chassis ground - Approx. 0V
  1. Ignition "OFF".
  2. Disconnect the auxiliary battery (-) terminal.
  3. Disconnect the electrical connector(s) from the concerned component.
HO2S (bank1, sensor1) connector 2 (nernst voltage) Chassis ground - ∞ (infinity)Ω
HO2S (bank1, sensor1) connector 6 (trim resistor) Chassis ground - ∞ (infinity)Ω
HO2S (bank1, sensor1) connector 3 (pumping line) Chassis ground - ∞ (infinity)Ω
HO2S (bank1, sensor1) connector 2 (nernst voltage) ECM connector 58 (nernst voltage) Approx. below 1Ω
HO2S (bank1, sensor1) connector 1 (virtual ground) ECM connector 43 (virtual ground) Approx. below 1Ω
HO2S (bank1, sensor1) connector 6 (trim resistor) ECM connector 44 (trim resistor) Approx. below 1Ω
HO2S (bank1, sensor1) connector 3 (pumping line) ECM connector 59 (pumping line) Approx. below 1Ω

Good 

No Good