Heated Oxygen Sensors (HO2S) -G39- and - G108-, Checking Aging

Heated Oxygen Sensor (HO2S) -G39- And Heated Oxygen Sensor (HO2S) 2 - G108-, Checking Aging

Requirement

- Coolant temperature at least 80 degree C see Display group 004, display zone 3

Work sequence

- Connect vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 - Engine electronics" from list. Engine must be idling. Connecting VAS 5051 Scan Tool

Indicated on VAS 5051:







- From list -1- select diagnostic function "04 - Basic setting".

Indicated on VAS 5051:







1 Enter display group
- Use keypad -2- to enter "034" for "Display group number 34" and confirm by touching Q key.

Indicated on VAS 5051:







- Activate basic setting by touching key -A-.

Condition
- Engine idling
- Continue with test as soon as "Test ON" appears in display zone 4.

NOTE: This process may take a few minutes.

- Check display in corresponding zones.

Display Group 034:

Note on display zone 2:
Exhaust gas temperature displayed is a value calculated from engine speed and engine load. Temperature displayed during test must be greater than 250 degree C, as otherwise test is not started or will be terminated.

Note on display zones 3 and 4:
The period indicates the time between two voltage step changes (e.g. rich - lean - rich) of the oxygen sensor and is thus an indication of the aging status of the oxygen sensor. If the specified time is exceeded, display zone 4 shows B1-S1 n.OK.

(Continuation)
If reading does not match specification in display zones 3 or 4:
- Replace Heated Oxygen Sensor (HO2S) -G39-, bank 1 (B1-S1).
- Touch <- key.

Indicated on VAS 5051:







1 Enter display group
- Use keypad -2- to enter "035" for "Display group number 35" and confirm by touching Q key.

Indicated on VAS 5051:







- Activate basic setting by touching key -A-.

Condition

- Engine idling

- Continue with test as soon as "Test ON" appears in display zone 4.

NOTE: There may already be a diagnostic result in display zone 4 (e.g. B2-S1 OK), as certain diagnostic procedures are implemented simultaneously by the engine control module.

Display Group 035:

Note on display zone 2:
Exhaust gas temperature displayed is a value calculated from engine speed and engine load. Temperature displayed during test must be greater than 250 degree C, as otherwise test is not started or will be terminated.

Note on display zones 3 and 4:
The period indicates the time between two voltage step changes (e.g. rich - lean - rich) of the oxygen sensor and is thus an indication of the aging status of the oxygen sensor. If the specified time is exceeded, display zone 4 shows B2-S1 n.OK.

- Terminate function "04 - Basic setting" by touching <- key.

(Continuation)
If reading does not match specification in display zones 3 or 4:
- Replace Heated Oxygen Sensor (HO2S) 2 - G108-, bank 2 (B2-S1).