DTC Advanced Diagnostics: P04A0 (3.0L Engine)

DTC P04A0:  Left Active Exhaust System Mechanical Failure

General Description 

Courtesy of HONDA, U.S.A., INC.

The left active exhaust actuator runs a self-diagnostic function to monitor if there is electrically or mechanically failure. The powertrain control module (PCM) communicates with the left active exhaust actuator via local interconnect network (LIN) line and detects failure by monitoring the self-diagnostic information. If any of the following condition occurs, the PCM detects a malfunction and stores a DTC.

• The commanded active exhaust actuator position is not satisfied
• The received self-diagnostic information is abnormal
• Fails communicating by LIN

Monitor Execution, Sequence, Duration, DTC Type 

Execution	Continuous
Sequence	None
Duration	10 seconds or more
DTC Type	Two drive cycles, MIL off

Enable Conditions 

Condition
Vehicle	ON mode
Other	LIN communication is OK
	Active exhaust actuator calibration is completed

Malfunction Threshold 

Any of the following condition occurs:

• The commanded active exhaust actuator position is not satisfied for at least 5 seconds
• The received self-diagnostic information is abnormal
• Fails communicating by LIN*

*: It is detected only when forced operation is requested by the HDS.

Possible Cause 

• Left active exhaust actuator flap blocked (ex. rock, stick, ice)
• Left active exhaust actuator calibration failure
• Left active exhaust actuator failure
• LIN communicaton failure*

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC, the freeze data, and the on-board snapshot are stored. The MIL does not come on.

Conditions for clearing the DTC 

The Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.