P22C2

Code

Generic P — Powertrain

O2 Sensor Pumping Current Trim Circuit/Open Bank 2 Sensor 2

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 34 RU: 34

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Page language: EN

Causes

Broken/open wiring or connector between sensor and PCM/ECM
Corroded/loose connector or pin(s) at sensor or module
Failed wideband/UEGO oxygen sensor (pump cell open)
Short to voltage or ground in the pump/current circuit
Poor sensor ground or reference supply issue
Water/contamination damage to sensor or connector

Symptoms

Malfunction indicator lamp (MIL) illuminated
Stored DTC P22C2 (and possibly related O2 codes)
Failed emissions test / increased tailpipe emissions
Reduced ability to monitor catalyst efficiency (ready monitor may not set)
Possible poor fuel trim history or drivability alarms (less likely from downstream sensor)

What to check

Retrieve freeze frame and pending codes with a scan tool; note related O2 or heater codes
Visual inspection of Bank 2 Sensor 2 connector and wiring for corrosion, damage, pin push‑out, water ingress or melting
Backprobe sensor connector while monitoring live data (pump current, lambda) with scan tool
Check for continuity between sensor pump circuit pin and PCM pin; check for open, short to ground, and short to battery
Measure resistance and/or expected voltages on sensor harness per vehicle wiring diagram (pump reference, heater supply, ground)
Wiggle test wiring while watching live data/scan tool for intermittent faults

Signal parameters

Pump cell (wideband) expected to be near zero current at stoichiometric; active pump current will vary positive/negative with rich/lean conditions
Typical pump current operating range: small milliamps ± (manufacturer dependent) — open circuit will show no pump current or out‑of‑range value
Sensor warm‑up time: pump cell should respond when the sensor reaches operating temperature (downstream sensor reaches operating temperature later than upstream)
Heater circuit (if present) should show correct supply voltage and continuity; heater failure is a separate circuit but can affect sensor operation

Diagnostic algorithm

Connect a capable scan tool, read DTCs and freeze frame; record related O2/heater codes and live sensor data for Bank 2 Sensor 2.
Perform a visual inspection of the sensor, harness, and connector for damage, corrosion, or water entry. Repair obvious issues.
With ignition on (engine off) backprobe sensor connector and verify reference power/ground pins per wiring diagram. Check for open/short between sensor pump circuit and PCM.
Monitor live pump current (or lambda/pump cell) while cranking and during warm‑up. An open will typically show a no‑signal or out‑of‑range value when compared to a good sensor or bank 1 sensor 2 data.
Perform continuity check from sensor pump pin to PCM pump pin; check for short to battery (VBatt) and short to chassis ground.
Wiggle wiring harness while observing live data to reveal intermittent opens. Repair chafed or broken wiring as needed.
If wiring and connectors test good, replace the Bank 2 Sensor 2 (OE or manufacturer‑specified wideband sensor) and clear codes.
After repair or replacement, erase codes and perform a road test to verify DTC does not return and that downstream sensor data and monitors operate normally.
If the new sensor does not correct the issue, test PCM outputs/grounds and consult manufacturer-specific wiring diagrams and PCM test procedures; repair or replace PCM only after confirming upstream diagnostics.

Likely causes

Connector/wiring open or intermittent at Bank 2 Sensor 2 (most common)
Failed downstream wideband/UEGO sensor pump cell
Corrosion or bent/missing terminal at sensor or module connector
Short to battery or chassis ground in pump circuit

Fault status

⚠️ Status

Open or out‑of‑range condition detected in O2 sensor pump current trim circuit — Bank 2 Sensor 2. Downstream wideband pump‑cell signal is missing or invalid, which can prevent proper post‑catalyst monitoring and set the MIL.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours