Component Location
General Description
The Lambda closed-loop control system is included in the engine’ s control system. The control system regulates the lambda upstream with the HO2S signal. Rich mixtures generate high concentrations of CO, H2, and HC. Lean mixtures generate the high concentrations of NOx, and free oxygen.
DTC Description
If the lambda controller reaches the maximum or minimum threshold, then feedback control is no longer possible and emissions will be increased. The ECM sets DTC P0173 if no proportional fuel adaptation occurs for a defined time after the lambda controller has reached its minimum or maximum threshold.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Monitoring deviation of lambda controller
| Air leakage or restriction in intake or exhaust system
Dirty engine oil or oil level too high
Front HO2S or MAFS contamination
Fuel system
EVAP system
Faulty sensor signals
|
Enable Conditions | Canister purge solenoid closed
Coolant temperature>60°C(140°F)
|
Threshold Value | Lambda controller = +/-32%
|
Diagnostic Time | 2 min
|
MIL On Condition | 2 Driving Cycles
|