Mazda MPV 2001, code P1518 , and P1512, what is the problem?

Idle Charge Actuator Mechanical malfunction. May have a bad O2 sensor or actuator.

Trouble Code: P1518

Intake Manifold Runner Control Shutter Valve (Stuck Open)
Possible Causes:


IMRC control circuit shorted to ground or to system power (B+) . IMRC shutter valve actuator is stuck closed . IMRC vacuum hose is loose or disconnected. PCM has failed .From the Mazda Repair guides.

The code involves IMRC runner valves in the intake manifold. I would do some internet research for the code and see if the repairs are within your abilities.

DTC P1512 - VARIABLE TUMBLE CONTROL SYSTEM (VTCS), STUCK CLOSED
The air intake hose that goes from the air filter/mass airflow sensor to the throttle body they are common to crack. This air leak can cause a lean condition if that checks out ok then the issue is usually a faulty mass air flow sensor .This would need to be checked next.

Usually the actuator valve is stuck closed. These are the most common causes of the P1512 and possible causes are:
* ECT sensor malfunction.
* MAF sensor malfunction.
* IAT sensor malfunction.
* EGR boost sensor malfunction
* TP sensor malfunction.
* CKP sensor malfunction
* VTCS solenoid valve malfunction.
* VTCS shutter valve stuck closed.
* VTCS shutter valve actuator stuck closed.
* Short circuit between PCM and VCTS solenoid valve.
* PCM malfunction.

I would start with the mass air flow sensor this can cause all these issues. Then the cat. This would be the next step.

I hope this helped (remember to rate and comment this answer).

P1518- Intake manifold runner control fault- stuck open
p1520-intake manifold runner control fault
p0306-cylinder 6 misfire detected

good luck

no such code exists in my generic codes ,neither in my mazda codes

P0031 - most likely pointing to a failed O2 sensor (bank 1 sensor 1 is located before the catalytic converter)

P0421 - failed catalytic converter or a failed O2 sensor

P1512 - intake manifold shutter valve is stuck - may be caused by the O2 sensor, but may not

I recommend replacing your O2 sensor first and see what happens

Possible problem is carbon build up in intake runners..remove top intake and clean runners..

I had the same problem and it happened at high speed on an Interstate Mountain (Hwy 5 from Kelowna to Meritt).... so scared but car ran fine all the way.... so hope it goes away.... I had the check engine light removed and hope it does not reappear