Codes P1403/P1404/P1405, EGR Error: Notes

Codes P1403, P1404 and P1405 are EGR flow test failures. PCM tests the medium and large EGR solenoid valves by cycling each of them on momentarily while monitoring engine RPM. When a solenoid is on, PCM expects to see a drop in engine RPM. Codes P1403, P1404 and P1405 will set when the following conditions are present.

• Engine coolant temperature is greater than 183°F (84°C).
• Vehicle is in coast down condition.
• Vehicle not in decel fuel cutoff.
• Heated oxygen sensor voltage greater than .57 volt.
• Vehicle in 1st or 2nd gear.
• Vehicle speed is greater than 20 MPH.
• A/C clutch not engaged.
• RPM 925-1063 (to run EGR No. 1 test).
• RPM 975-1188 (to run EGR No. 2 test).
• RPM 1000-1488 (to run EGR No. 3 test).

Code P1403 will set if expected drop is not seen 10 out of 12 times when EGR solenoid No. 1 is tested. Code P1404 will set if expected drop is not seen 9 out of 12 times when medium EGR solenoid No. 2 is tested. Code P1405 will set if expected drop is not seen 4 out of 5 times when large EGR solenoid No. 3 is tested. PCM will illuminate Malfunction Indicator Light (MIL) when codes set.

1. A change in engine RPM should be detected as each solenoid is cycled on.