Mixture Is Too Lean In Part Load Range [Start Here]

[1] Self adaptation of mixture formation: The mixture is too lean in the part load range. [P0172]

Note Fault code P2029 /P2046





Procedure Fault code P2029/P2046

Fig. legend/ fig.





- G3/2x1 (O2 sensor upstream TWC connector)
- 003 Multimeter

Test sequence
- Separate plug connection G3/2x1 (O2 sensor upstream TWC connector).
- Connect multimeter to engine wiring harness connector between pins 2 and 6.

Specified value
- Resistor [57...67]

Question: Is the measured value okay?

No
- The measured value is not o.k

Possible cause and remedy
- Check line(s) of components G3/1 (O2 sensor downstream TWC) and G3/2 (O2 sensor upstream TWC) for incorrect routing and damage.
- Disconnect plug at engine wiring harness (component N3/10 (ME-SFI control module)) and check connection for damage.
- Check connectors G3/1x1 (O2 sensor downstream TWC connector) and G3/2x1 (O2 sensor upstream of TWC connector) for proper seating, contacts and latching.
- Repair or replace lines and connector in accordance with current circuit diagram.

**End of test**

Yes

Test 1: Check component G3/2 (O2 sensor upstream TWC) Test 1: Check Component G3/2 (O2 Sensor Upstream TWC)
Test 2: Selfadaptation of mixture formation Test 2: Selfadaptation of Mixture Formation
Test 3: Inspect charge air system for leaks Test 3: Inspect Charge Air System For Leaks