P1404

Read the instructions below then start the fault diagnostic procedure.

Symptom: Abnormal idling.

P1404

Fault symptoms

•	Abnormal idling.

On-Board Diagnostics

Type of diagnosis:

-	Continuous.

Enable criteria:

-	Battery voltage should be 10.2-15.8 V.

-	P1636 or P1637 should not be detected.

-	Rpm changes between two measurements should not exceed a difference of 40 rpm.

-	The difference between two injections should not exceed 1.5 mm 3 /C.

-	EGR flow must be more than 26 %.

-	These conditions should be fulfilled for 3 seconds before diagnostics run.

Fault criteria:

-	The EGR position is 3.5mm higher than desired.

Dependents:

-

None.

System reaction to a fault:

-	EGR switched off.

OK report:

-	Fault criteria not fulfilled.

Fault handling: (See section Fault handling III, other emissions-related components and functions for more information)

-

Type III.

Diagnostic help

Fault diagnosis concerns an electrical fault in connecting leads or in the sensor.

Functions in the diagnostic tool related to the fault:

-	Read values: Target EGR Valve Position, EGR Valve Position. EGR PWM signal.

-	The EGR function is switched off after 1 minute of idling (EGR valve closed). As soon as the accelerator pedal is touched, EGR control is reactivated.

See also description of read value under "Read Values" menu for more information.

Checking the wiring

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.