P1540

Lysholm air bypass valve (ABV) control system malfunction

Detection Conditions

• Actual charged-air pressure is higher than target charged-air pressure by 19.7 kPa or more
• ECU reduces charged-air pressure but air temperature sensor (on the Lysholm compressor) does not indicate a drop to 150 degrees C or below

Diagnostic Support Notes

• This is a continuous monitor (CCM)
• Check engine indicator illuminates if the ECU detects the above malfunction condition during two drive cycles
• PENDING CODE is available
• FREEZE FRAME DATA is available
• DTC is stored in ECU memory

Possible Causes

• ABV actuator malfunction
• ABV vacuum control solenoid valve malfunction
• ABV vent control solenoid valve malfunction
• Intercooler bypass valve actuator is stuck closed
• Intercooler bypass solenoid valve malfunction
• MAP sensor malfunction
• MAP sensor solenoid valve malfunction
• ABV system related vacuum hose is restricted or leaking
• Intake air temperature (Lysholm compressor) sensor malfunction
• Lysholm compressor malfunction
• ECU malfunction

[P1540 - From 2002 Mazda Millenia factory service manual]