DTC P0137: HEATED OXYGEN SENSOR NO. 2 CIRCUIT - LOW VOLTAGE Chevrolet Venture I

Note. For circuit reference, see WIRING DIAGRAMS article.

Circuit Description

Three-Way Catalyst (TWC) system is used to control emissions. PCM uses signal from Heated Oxygen Sensor 2 (HO2S 2) behind TWC to read efficiency of TWC. PCM will set this DTC if TWC oxygen storage capacity is less than a predetermined threshold.

For duplication of DTC, ensure

1. No active misfire, fuel injector circuit, EVAP system, fuel trim, EGR system, TP, IAT, MAP, ECT, MAF or CKP sensor DTCs are set.
2. Closed loop commanded air/fuel ratio is 14.5-14.8:1.
3. Throttle angle is 3-40 percent.
4. HO2S 2 signal voltage remains less than 10 mV during normal closed loop operation.