Code 37 (Oxygen Sensor Heating)

OXYGEN SENSOR HEATING
Explanation
This trouble code is stored in the case of a break or short at:

- Oxygen sensor (heater pan)

- Sensor heating relay

- Wire from Digital Motor Electronic (DME) control unit to sensor heating relay

- Wires to oxygen sensor

- Output stage in the DME control unit

NOTE: The oxygen sensor heating relay is activated by the DME control unit I. For this reason, a detected defect is only stored in the DME control unit I.

Troubleshooting
- Perform component activation with tester. The relay is activated at 1 second intervals - this is audible. When the relay is active, ground is applied to terminal 85 of the relay (check with 12 V 3 W test lamp). In the case of defect "connection to sensor signal", check whether the defect is at the sensor or in its supply wire by monitoring the oxygen sensor.
- Proceed with displayed scan tool diagnostic instructions where applicable.