Feb 072014
 

My 2002 montero sport 3.0L gets a p0403 err and idles rough in park and even rough in drive at at stop. I notice my egr valve would move a little and stay in that position at idle and close back after I turn off car. When I remove the vacuum hose from the egr valve the engine would idle better. I found that my egr vaccum solenoid wouldn’t be energize so I disconnected the wire harness to the vacuum solenoid and ran test I found that hooking it straight to the battery it would click. I then check the wire harness and found that when I put my pos lead to one side the connector and touch the battery neg I had 12VDC, then I took the neg lead and tough the harness neg and tough the bat pos and I had 10.5VDC. I then retest the harness at the egr vacuum solenoid and had 10.5VDC. When I plugged it in to the solenoid the voltage went away. I check the ground back to the ECM it check good no break and not shorted. I did observe that the solenoid would click for a split second and then turn go off. What other issues could cause the egr vacuum solenoid not to function? Is there any other components that might cause the ECM to cut output to the vacuum solenoid.

  One Response to “2002 mitshubishi montero sport 3.0L”

  1. P0403 Mitsubishi – Exhaust Gas Recirculation Control Circuit

    Possible causes

    – Faulty EGR volume control solenoid valve
    – EGR volume control solenoid valve harness is open or shorted
    – EGR volume control solenoid valve circuit poor electrical connection
    – EGR temperature sensor and circuit

    When is the code detected?

    An improper voltage signal is sent to ECM through the valve

    P0403 Mitsubishi Description

    Early Exhaust Gas Recirculation (EGR) systems component s include and EGR Valve, and Engine Control Μodule (ECΜ) Controlled Vacuum Switch Valve or EGR Solenoid and an EGR Vacuum Μodulator. Depending on the engine and driving conditions, the ECΜ will control the EGR Solenoid which will operate the EGR Vacuum Μodulator to regulate the opening and closing of the EGR Valve.

    The EGR system on recently built vehicles uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECΜ. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECΜ does not issue the pulse signal. Α certain voltage signal is issued so that the valve remains at that particular opening.

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