Drivers typically notice the following when the downstream O₂ sensor on Bank 2 is inactive:
These signs arise directly from the PCM’s inability to receive voltage or signal data from the Bank 2 downstream sensor.
Corrosion, chafed insulation, or connector pin corrosion can interrupt the 5 V reference or ground to the sensor. A broken circuit registers “no activity” even if the sensor itself is functional.
The PCM generates the 5 V supply and reads the sensor’s voltage. Internal PCM circuitry can develop open‑circuit faults, shorted reference lines, or failed analog‑to‑digital converters, producing the same P0160 code.
The downstream O₂ sensor contains a heated element and a voltage‑producing element. Heater circuit failure or internal sensor burnout eliminates voltage output, leading the PCM to log “no activity.”
Occasionally, a corrupted PCM flash memory or an outdated calibration map prevents proper interpretation of the sensor’s signal, causing a false “no activity” condition.
– Connect a scan tool capable of O₂‑sensor monitoring. Verify that Bank 2 Sensor 1 shows normal switching while Sensor 2 reads 0 V or a constant voltage.
– Note fuel‑trim values; a persistently high short‑term fuel trim (> +10 %) supports the diagnosis.
– Locate the downstream O₂ sensor harness on the exhaust downstream of the catalytic converter.
– Perform a continuity test on the 5 V reference, sensor signal, and ground wires (typically 0.5 Ω or less).
– Clean and reseat the connector; spray dielectric grease to prevent future corrosion.
– With the ignition ON, measure voltage at the sensor connector. A healthy circuit shows ~5 V on the reference lead and a fluctuating sensor voltage (0.1–0.9 V).
– Absence of the reference voltage indicates a PCM supply issue; presence of reference voltage but zero sensor voltage points to sensor or heater failure.
– Use the scan tool’s “PCM communication” or “module test” function. Verify that the PCM can send and receive data on the CAN bus.
– If the PCM fails the communication test, proceed to module‑level diagnostics.
– When wiring is intact and PCM supplies proper voltage, replace the downstream O₂ sensor. Use a sensor that matches the vehicle’s emission specifications; after installation, clear codes and verify live data for proper switching.
– If the PCM’s reference voltage is missing but the wiring is sound, re‑flash the PCM with the latest calibration file. Many OEMs release updates that correct sensor‑circuit handling.
– Persistent “no activity” after wiring repair, sensor replacement, and re‑programming indicates internal PCM failure. Replace the PCM with a VIN‑matched unit and have it programmed to the vehicle’s specifications.
Cost Estimates
Modern control modules are integrated with security, immobilizer, and emissions systems. When internal circuitry degrades, repair often provides only a temporary fix, and repeated faults can return after a short drive cycle. In such cases, replacing the PCM ensures long‑term reliability.
Flagship One specializes in VIN‑matched control modules, providing a plug‑and‑drive solution backed by a comprehensive warranty.
Our modules are pre‑programmed to the exact software version required for your vehicle, eliminating dealer‑only re‑flash delays. By sourcing a replacement from Flagship One, you receive a tested, compatible unit that restores full PCM functionality without the risk of mismatched calibrations.
Service Recommendation: Most issues related to this fault are diagnosed and corrected through inspection, wiring repair, and calibration rather than module replacement. For modules not typically replaced through aftermarket suppliers, diagnosis and repair should be performed by a certified automotive technician with access to factory service information and tooling.