Signal amplitude plausibility error : In order to determine the signal amplitude plausibility, the PCM monitors front HO2S signal level from rich to lean and from lean to rich. The PCM sets DTC P0134, If the difference of the signal transition level is too small.
Signal plausibility error during fuel cut-off : PCM sets DTC P0134, if the HO2S(B1S1) signal is too high during fuel cut-off period for a predetermined time.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case 1 |
•
Signal plausibility during fuel cut-off | 1. Poor connection or damaged harness 2. HO2S contamination |
Case 2 |
•
Signal amplitude plausibility | ||
Enable Conditions | Case 1 |
•
O2 sensor operative readiness detected
•
O2 sensor pre-heating phase finished
•
12g< Integrated Mass Air Flow since Fuel Cut-Off begin <250g
•
No relevant failure
•
10V< Battery voltage <16V | |
Case 2 |
•
O2 sensor pre-heating phase finished
•
5< Number of lambda controller P jumps since Lambda control activation
•
Closed loop lambda controller output not limited to min./max. limit
•
O2 sensor signal lean half period <2sec.
•
O2 sensor signal rich half period <2sec.
•
No relevant failure
•
10V< Battery voltage <16V | ||
Threshold Value | Case 1 |
•
HO2S(B1S1) voltage at fuel-cut mode > 0.3V | |
Case 2 |
•
Upstream O2 sensor signal amplitude < 0.20 V | ||
Diagnostic Time | Case 1 |
•
5 sec. | |
Case 2 |
•
120 sec. | ||
MIL On Condition |
•
2 Driving Cycles | ||
