Test H: Step 17
17) Check HEGO Sensor For Short to Ground With key off, breakout box installed, and ECA disconnected, set DVOM to 200-k/ohm scale. Disconnect HEGO sensor. Measure resistance between PWR GND and HEGO SIGNAL at the HEGO sensor connector. On trucks with 4-wire sensors, measure resistance between PWR GND, HEGO GND and HEGO SIG at the HEGO sensor connector. If resistance is less than 10 k/ohms, replace HEGO sensor, remove breakout box, reconnect all components and repeat QUICK TEST. If resistance is greater than 10 k/ohms, go to the appropriate following procedure.
- Engines equipped with MAP sensor: Go to next step.
- Engines equipped with MA (Mass Air Sensor): Remove breakout box, reconnect HEGO sensor, replace ECA and rerun QUICK TEST.