Chrysler
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    HO2S Heater Circuit Conditions
Cause:
    Cold engine startup requirement met (ECT sensor input less than 147°F, BTS ambient air input within 27-50°F of the ECT input), engine at idle speed, then the test started and the PCM detected that the rear HO2S-12 signal was more than 0.3v for 30-90 seconds.

Ford
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    HO2S Heater Circuit Conditions
Cause:
    Engine running for 1 minute, then the PCM detected an open or short in the HO2S heater circuit

Generic
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    O2 Sensor Heater Circuit

GM
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    HO2S Heater Circuit Conditions
Cause:
    No HO2S-12 codes set, engine running, system voltage 11-15.5v, TWC temperature from 626-968°F, then the PCM determined that the HO2S-12 heater resistance was out-of-range for 15 seconds

Honda
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    Secondary air injection (AIR) pump - malfunction
Cause:
    Wiring, AIR pump relay, AIR pump, ECM