Check Of Monitoring Conditions For Active Test
The diagnostic principle uses the precise measurement of the A/F ratio fed into the catalyst. This requires verification that the engine is running under acceptable operating conditions. If such operating conditions are no longer present, the monitor is terminated and restarted only some time later.
Diagnosis Of Fuel Delivery System
Faults in the fuel delivery system can occur which cannot be compensated for by the adaptive pilot control.
In this case the adaptive values leave a predetermined range.
If the adaptive value is outside a plausible range, then the MIL is illuminated and a fault code is stored.
Scheme 321
Scheme 322
Power Stage Diagnosis
During power stage on and off, the control signal (input) of the power stage is compared to its output signal. Also the heater current is checked against a minimum limit. With these checks open circuit as well as short to either ground or battery voltage can be detected. Fault codes are set as appropriate.
Scheme 323
During power stage on and off, the control signal (input) of the power stage is compared to its output signal. Also the heater current is checked against a minimum limit. With these checks an open circuit as well as a short to either ground or battery voltage can be detected.
Scheme 324
9.9.3. Test Results reported in Mode 6 of J1979
| Test ID/Comp. ID | Monitored Component | Possible Range | Hex Code Factor |
|---|---|---|---|
| TID1 | Catalyst monitoring | ||
| CID1 | Catalyst monitoring of catalyst 1 sum of the determined ratios | 0...65535 | 0...FFFF H |
| CID2 | Catalyst monitoring of catalyst 2 sum of the determined ratios | 0...65535 | 0...FFFF H |
| TID3 | Secondary air system monitoring | ||
| CID1 | Relative secondary air mass Bank 1 | 0...511,9922 | 0...FFFF H |
| CID4 | Relative secondary air mass Bank 2 | 0...511,9922 | 0...FFFF H |
| TID5 | Evaporative system monitoring | ||
| CID2 | Pump period time while leakage monitoring | 0...655.35 s | 0...FFFF H |
| CID1 | Changing of fuel trim after opening the purge valve | 63,9972...0...63,9972 | 0...7FFF...8000...FFFF H |
| CID8 | Idle speed change by opening the purge valve | 8191,75...0...8191,75 | 0...7FFF...8000...FFFF H |
TEST RESULTS CHART