PCM sets DTC P06A4 if the PCM detects reference voltage of APT is lower than threshold value.
| Item | Detecting Condition | Possible Cause | |
| Case 1 | DTC Strategy | 
										•
									 Electrical check | 1. Short to ground in power circuit 2. Poor connection or damaged harness 3. Faulty APT | 
| Enable Conditions | 
										•
									 IG "ON" | ||
| Threshold Value | 
										•
									 Short to ground 
										•
									 APT power supply voltage < 0.7 V | ||
| Case 2 | DTC Strategy | 
										•
									 Electrical check | |
| Enable Conditions | 
										•
									 IG ON | ||
| Threshold Value | 
										•
									 Sensor or harness problem 
										•
									 0.7 V ≤ APT power supply voltage < 4.5 V | ||
| Diagnostic Time | 
										•
									 0.1 sec. | ||
| Mil On Condition | 
										•
									 1 Drive Cycle | ||
( ※ APT : Air-Con Pressure Transducer )