Code
P2253
Generic
P — Powertrain
O2 Sensor Negative Current Control Circuit High Bank 1 Sensor 1
AI status
Completed
Completed
100%
Causes
- Open or short in the O2 sensor negative current/control wiring
- Corroded, loose or contaminated connector at the sensor or ECM
- Failed wideband (UEGO) oxygen sensor (Bank 1, Sensor 1)
- Poor engine or ECM ground
- Internal ECM fault or failed driver transistor
- Aftermarket or damaged sensor installation
Symptoms
- Malfunction Indicator Lamp (MIL) / Check Engine Light ON
- Poor idle quality, hesitation, or drivability issues
- Increased fuel consumption or rich/lean fuel trim symptoms
- Failed emissions test or elevated tailpipe emissions
- Reduced performance or limp-home strategy (rare)
What to check
- Read and record freeze frame and live data for Bank 1 Sensor 1 using a capable scan tool
- Visual inspection of sensor, connector, and wiring for damage, corrosion, or pin push-out
- Wiggle test wiring while monitoring live data to reproduce the fault
- Check engine and ECM grounds for corrosion or loose bolts
- Measure resistance and continuity of the sensor harness; check for short to ground or battery
- Compare sensor heater resistance to specification (if applicable) and power/ground supply voltages
Signal parameters
- Bank 1 Sensor 1 (front) is the upstream oxygen sensor controlling fuel trim
- Wideband/UEGO sensors report pump current; abnormal high negative pump current triggers this code
- Expected: pump current values within manufacturer range for stoichiometric operation (varies by sensor type)
- Heater circuit should have proper supply voltage and return; sensor signal/ground should not be shorted
Diagnostic algorithm
- Retrieve codes, freeze frame, and confirm P2253 is current. Clear codes and attempt to reproduce.
- Perform a careful visual inspection of Bank 1 Sensor 1 connector and harness. Repair any physical damage or corrosion.
- Verify proper power and ground at the sensor connector (heater supply and sensor ground/reference as applicable).
- Check continuity between the sensor negative control pin and the ECM pin. Look for short to chassis ground or battery.
- Backprobe and monitor the sensor control/pump current signal with a manufacturer scan tool or oscilloscope while engine is running; look for abnormal high negative current or noise.
- If wiring and connectors are good, swap with a known-good identical sensor (or harness) if available, or replace the oxygen sensor and re-test.
- If code returns after sensor and wiring replacement, suspect ECM output driver fault; verify with manufacturer diagnostic procedures before replacing ECM.
- After repair, clear codes and perform a road test to confirm the fault does not return and that fuel trims and emissions-related parameters are within expected ranges.
Likely causes
- Short to ground on the sensor negative control conductor
- High resistance in the sensor harness or connector causing incorrect current measurement
- Contaminated sensor element producing abnormal pump currents
- Heater circuit interaction or short affecting the control circuit
- Connector pins pushed out, corroded, or water intrusion at sensor pigtail
Fault status
Status
ECM detected excessive negative pump current on the Bank 1 Sensor 1 oxygen sensor control circuit. Possible wiring, sensor, or ECM driver fault affecting proper air/fuel control.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Repair manuals
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