DTC P0506-00: P151B-00: IAC System Rpm Lower Than Expected: Notes

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0506:00	IAC system RPM lower than expected
DTC P151B:00	IAC system problem
DETECTION CONDITION	DTC P0506:00 The actual idle speed is lower than expected by 100 rpm for 14 s , when the brake pedal is depressed (brake switch is on). NOTE: If the atmospheric pressure is less than 72.2 kPa {0.736 kgf/cm ² , 10.5 psi} or the intake air temperature is below -10 °C {14 °F} , the PCM cancels the diagnosis of DTC P0506:00. Diagnostic support note This is a continuous monitor (CCM). The check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. DTC is stored in the PCM memory. DTC P151B:00 The PCM cannot control the idle speed toward the target idle speed during the KOER self test. Diagnostic support note The check engine light does not illuminate. FREEZE FRAME DATA (Mode 2)/Snapshot data is not available. DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	Not applicable
POSSIBLE CAUSE	A/C magnetic clutch malfunction Drive-by-wire control system malfunction Malfunction in injection amount measurement system (refer to DTC P0101:00 ) Purge solenoid valve malfunction Air cleaner element restricted Throttle body passage blockage Engine malfunction Insufficient engine compression Generator control circuit malfunction PCM malfunction
System Wiring Diagram	Not applicable

CAUTION:

Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.