DIAGNOSTIC TROUBLE CODE (DTC) - P1404 ELECTRIC EXHAUST GAS RECIRCULATION CLOSED

Knowing The Circuit

  • By any chance if high combustion temperatures are created by oxides of nitrogen then An Electric Exhaust Gas Re-circulation (EEGR) system which is the chief feature of this system will be boosted to counter this.
  • This is done by supplying small amounts of exhaust gases back into the combustion chamber.
  • Combustion temperatures are minimized as soon as the air/ fuel mixture dilutes the exhaust gases.
  • The EEGR valve has been specially designed to generate exhaust gases to the engine without using intake manifold vacuum.
  •  This valve regulates exhaust flow entering the intake manifold from the exhaust manifold through an orifice with an ECM controlled pintle.
  • The pintle position is monitored by the ECM using inputs from the Throttle Position (TP) and the Manifold Absolute Pressure (MAP) sensor.
  • This task over, the ECM then directs the EEGR valve to operate as necessary by controlling an ignition signal through the ECM.
  • The ECM further monitors the results of its command through a feedback signal.
  • The desired EEGR position can be checked with the help of a scan tool.
  • A voltage signal representing the EEGR valve pintle position is sent to the ECM by a 5 volt reference and a ground to the EEGR valve.
  • The scan tool can also be used here to note the feedback signal which is the actual position of the EEGR pintle.
  • The correct EEGR position should always be close to the commanded or Desired EEGR position.

This Diagnostic Trouble Code (DTC) is capable of identifying an open or short circuit.

 

Conditions for Setting THE DTC

DTC is set when:

  • EEGR circuit high voltage.

 

 

What happens when DTC sets?

When will DTC clear?

1) The Malfunction Indicator Lamp (MIL) will glow

1) The MIL will automatically turn off after four consecutive ignition cycles in which the diagnostic runs without faultlessly.

 

2) The ECM will record operating conditions when the diagnostic fails which will be stored in the Freeze Frame and Failure Records will  buffer

2) A history DTC will clear after 40 consecutive warm-up cycles without a fault

3) A history DTC is stored

3) The Scan Tool will be handy in removing the all DTCs.

 

4) EEGR is paralyzed.

 

4) Dissociating the ECM battery feed for a time beyond 10 seconds

 

 

DIAGNOSTICS  TOOLS:

  •  Moisture related with exhaust systems might result in the EEGR valve to freeze and malfunction in cold weather occasionally.
  •  This problem will be solved when the vehicle is taken to any warm shop for repairs and the affected part duly repaired.
  • The error in can be easily noted by comparing the Actual EEGR and the desired EEGR positions on a cold vehicle with a scan tool.
  • Note the Engine Coolant Temperature (ECT) and then check the Freeze Frame data to ensure that the DTC was set when the vehicle was cold.

                                       TABULATION OF THE STEPS TO BE UNDERTAKE

                                      DTC P1404 - Electric Exhaust Gas Recirculation Closed

Step

Task

Value(s)

R   E     S

U    L    T

1

Carry out an EOBD System Check.

Task Done?

-

IF  YES       THEN

Follow Step 2

IF  NO       THEN

Go to "On-Board Diagnostic System Check"

2

1) Turn the ignition switch to ON letting the engine OFF.

2 ) Insert the scan tool.

3)  Direct the electric exhaust gas recirculation (EEGR) valve to the required values.

Do you see any parity between the Actual EEGR Position and the desired EEGR position?

25%, 50%, 75%, 100%

IF  YES       THEN

Follow Step 19

IF  NO  

     THEN

Follow Step 3

3

1) Take the ignition switch to ON keeping the engine OFF.

2) Dissociate the EEGR valve electrical connector.

3)  Examine the 5volt reference circuit at terminal 2 to the EEGR valve, ensuring that the digital voltmeter (DVM) is connected to ground.

Is the DVM anywhere near the desired value?

5V

IF  YES       THEN

Follow Step 4

IF  NO   

   THEN

Follow Step 5

4

Jumper the 5 volt reference circuit to the signal circuit at terminals 2 and 3.

 

Do you see that the actual EEGR position reads the value needed?

100%

IF  YES       THEN

Follow Step 6

IF  NO   

    THEN

Follow Step 7

5

1) Attach the test light to B+.

2)Examine the 5 volt reference circuit to the EEGR valve.

Do you see the test light responding?

-

IF  YES       THEN

Follow Step  6

IF  NO   

    THEN

Follow Step  7

6

Thoroughly examine the 5 volt reference and signal circuit to see whether a poor connection or proper terminal tension exists and repair if necessary.

 

Work Done?

-

IF  YES       THEN

Follow Step 12

IF  NO    

  THEN

Follow Step 7

7

1) Now connect the test light to B+.

2)       Survey the signal circuit at terminal 1 to the EEGR valve.

Does the test light respond?

-

IF  YES       THEN

Follow Step 8

IF  NO   

   THEN

Follow Step 9

8

Look out for a high voltage in the EEGR valve 5 volt reference circuit. If you spot any,then repair as necessary.

 

Does a repair necessitate?

-

IF  YES       THEN

Follow Step 12

IF  NO   

  THEN

Follow Step 9

9

Change the EEGR valve.

 

Task Done?

-

IF  YES       THEN

Follow Step 12

-

10

Watch out for a high voltage in the EEGR valve signal circuit and repair if needed.

 

Does a repair necessitate?

-

IF  YES       THEN

Follow Step 12

IF  NO   

   THEN

Follow Step 11

11

Change the engine control module (ECM).

 

Work Done?

-

IF  YES       THEN

Follow Step 12

-

12

1)  Clear the Diagnostic Trouble Codes (DTCs) taking the Scan Tool.

2)  Start the engine and idle at normal operating temperature.

3)       Regulate the vehicle within the conditions for setting the DTC as mentioned in the text.

Do you see that the scan tool indicates that this diagnostic was run and passed?

-

IF  YES       THEN

Follow Step 13

IF  NO   

   THEN

Follow Step2

13

Check if any additional DTCs are set.

 

Do you see any undiagnosed DTC still being displayed?

-

IF  YES       THEN

Go to Applicable DTC table

IF  NO     

 THEN

 The System of your car is OK.