CLOSED LOOP Tab
Enable Closed Loop
- Enable Closed Loop - This enables closed loop AFR control and O2 sensor diagnostics.
ENABLE NARROW BAND CLOSED LOOP
- NBO2 Closed Loop - If Enable Closed Loop is set and this is set, closed loop will use the narrow band O2 (NBO2) sensor input. If this is not set, the wideband O2 sensor (WBO2) input is used.
- NBO2 Static Thresholds - If enabled, static thresholds are used to determine the rich/lean switchover point, otherwise, dynamic thresholds are used.
- MIN ECT WARM START - Minimum warm start ECT for closed loop.
- MIN ECT COLD START - Minimum cold start ECT for closed loop.
- WARM START ECT - Minimum ECT at startup for warm start.
- MAX RPM - Closed loop is disabled above this RPM.
- MAX MAF LOAD - Closed loop is disabled above this MAF Load.
- MAX MAP LOAD - Closed loop is disabled above this MAP Load.
- These parameters define the quadrant of the fuel map where closed loop is enabled.
FUEL TRIMS
These parameters define the minimum and maximum allowed closed loop O2 Trim.
- MIN TRIM - This defines the minimum amount of O2 Trim allowed.
- MAX TRIM - This defines the maximum amount of O2 Trim allowed.
- If either of these values is reached, and wideband closed loop is enabled, the WBO2 sensor DTC is set.
- TPS OPENING - If the throttle is opening less than this rate, it is considered steady.
- TPS CLOSING - If the throttle is closing less than this rate, it is considered steady.
- MAX RPM - Closed loop is re-enabled below this RPM after fuel cut.
- MIN RPM - Closed loop is disabled above this RPM during fuel cut transition.
- MIN ECT - Closed loop is disabled above this ECT during fuel cut transition.
- MIN SPEED - Closed loop is disabled above this vehicle speed during fuel cut transition.
Target AFR Table
This table sets the WBO2 target AFR based on RPM and engine load. If WBO2 closed loop is enabled,
O2 Trim is adjusted to control the AFR to the target value from this table.
Both load and RPM scales can be edited.
- LOAD SOURCE - Select the load source active during closed loop operation.
PID GAIN
PID Contol Parameters
These parameters set the Proportion/Integral/Derivative (PID) WBO2 closed loop contol parameters.
- PROPORTIONAL GAIN - Increase to decreaase rise time and steady state error. Decrease to decrease overshoot.
- DERIVATIVE GAIN - Increase to decrease overshoot and settling time.
- INTEGRAL GAIN - Increase to decrease steady state error.
- INTEGRAL MAX LIMIT - Sets the maximum amount of integral (accumulated error) allowed.
- UPDATE DELAY RATE - Sets the number of engine revolutions between evaluating WBO2 closed loop.
TIMERS
Wideband Closed Loop Timers
These timers control the delay before closed loop is re-enabled.
- SENSOR WARMUP TIMER - Closed loop is disabled for this amount of time after engine start to allow for WBO2 sensor warmup.
- RPM/LOAD IN RANGE TIMER - Closed loop is disabled for this amount of time after the RPM and load are within the range specified by Closed Loop Enable Parameters
- FUEL ENRICH SET TIMER - Closed loop is disabled for this amount of time after accel, decel, or knock enrichment is active.
- TPS TRANSITION TIMER - Closed loop is disabled for this amount of time after the throttle is steady (See STEADY THROTTLE parameters).
- FUEL CUT TIMER - Closed loop is disabled for this amount of time after FUEL CUT TRANSITION is active.
- REV LIMIT TIMER - Closed loop is disabled for this amount of time after hitting a rev limiter.
ERROR
WBO2 Closed Loop Error Parameters
- VOLTAGE ERROR DEADBAND - The WBO2 voltage error (difference between actual and target AFR) must be greater than this to cause a change in O2 Trim".
- AFR VALID MAX ERROR - The WBO2 voltage error (difference between actual and target AFR) must be less than this to set the "AFR Valid" flag (not logged).