P0402: EGR Flow Excessive Detected
WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
P0402 - EGR FLOW EXCESSIVE DETECTED
| Description: | The EGR system is monitored for undesired EGR flow during idle. The EGR monitor looks at the Differential Pressure Feedback EGR signal at idle and compares it to the stored signal measured during key ON and engine OFF. The test fails when the signal at idle is greater than at key ON engine OFF by a calibrated amount. | ||
| Possible Causes: |
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| Diagnostic Aids: | A DPFEGR PID reading that is greater at idle than during key ON and engine OFF by 0.5 volt or a rough engine idle may indicate a hard fault. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| Vehicles with an EGR System Module (ESM) | - | GO to PINPOINT TEST HH: EXHAUST GAS RECIRCULATION SYSTEM MODULE (ESM) Step 11. | GO to PINPOINT TEST HH: EXHAUST GAS RECIRCULATION SYSTEM MODULE (ESM) Step 11. |
| All others | - | GO to PINPOINT TEST HE: EXHAUST GAS RECIRCULATION (EGR) SYSTEMS Step 12. | GO to PINPOINT TEST HE: EXHAUST GAS RECIRCULATION (EGR) SYSTEMS Step 12. |