Diagnosis Of BOSCH Heated Oxygen Sensors (Ho2S)
WARNING: This page is about a different variant/trim than selected.
A full description of oxygen sensor monitoring, can be found in the service information Documents Tab/Diagnostics Section/OBD II System Information
CAUTION:
Diagnosis by substitution from a donor vehicle is NOT
acceptable. Substitution of control modules does not guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle
NOTE:
- Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests
- Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the manufacturer-approved diagnostic system).
- When performing voltage or resistance tests, always use a digital multimeter accurate to three decimal places, and with an up-to-date calibration certificate. When testing resistance always take the resistance of the digital multimeter leads into account.
- Inspect connectors for signs of water ingress, and pins for damage and/or corrosion.
- If DTCs are recorded and, after performing the pinpoint tests, a fault is not present, an intermittent concern may be the cause. Always check for loose connections and corroded terminals.
- Check JLR claims submission system for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific customer complaint and complete the recommendations as required.
The purpose of this document is to aid in the correct diagnosis of Bosch Heated Oxygen Sensors (HO2S) and to prevent unnecessary installation of new parts. It may be deemed after diagnosis that a particular sensor has failed, in this case it would be expected that only the failed sensor is replaced and NOT a complete vehicle set.