PO0401 code
10-20-2016, 06:11 PM
#1
Junior Member
Thread Starter
Join Date: Feb 2012
Location: Oklahoma
Posts: 64
PO0401 code
Hi everyone,
The check engine light just came on my 95 Maxima. I put a scanner on it and the code PO0401 came back which is "EGR flow insufficient." I'm hoping someone can tell me what this means and how I can fix/repair it. THe engine seems to run just fine but my OCD wont allow that dang light to stay on for very long. THank you in advance for any help you can provide.
The check engine light just came on my 95 Maxima. I put a scanner on it and the code PO0401 came back which is "EGR flow insufficient." I'm hoping someone can tell me what this means and how I can fix/repair it. THe engine seems to run just fine but my OCD wont allow that dang light to stay on for very long. THank you in advance for any help you can provide.
10-20-2016, 08:57 PM
#2
Senior Member
Join Date: Jan 2011
Location: Central AR
Posts: 3,041
The scanner code seems to be generic.
Here's a link to the check engine light codes.
https://maxima.org/forums/4th-genera...ere-first.html
0302
Diagnostic Trouble code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- The electrical harness or connectors (valve circuit open or shorted)
- The EGR valve is stuck closed
- Weak or dead battery
- The EGR passage is clogged
- Faulty EGR temperature sensor circuit
- A leak somewhere in the exhaust system
The EGR Volume Control Valve may be tested with an ohmmeter. Disconnect the electrical connector. Looking at the connector half which is attached to the EGRVCV with the latch at the 12 o'clock position you will see two rows of three terminals. The top row is numbered 1-3, right to left. The bottom row is numbered 4-6, right to left. Measure the resistance between these terminal pairs:
2 1
2 3
5 4
5 6
... all resistance values should be 20.9-23.1 ohms at 68 degrees F.
Reconnect the EGRVCV connector halves. Turn the ignition switch ON OFF repeatedly. Verify that the EGRVCV shaft moves smoothly forward backward according to the ignition switch position.
The Exhaust Gas Temperature Sensor may be tested with an ohmmeter. The specifications are ...
- at 32 degrees F, 0.68-1.11 Megohms
- at 122 degrees F, 0.09-0.12 Megohms
- at 212 degrees F, 0.017-0.024 Megohms
0305
Diagnostic Trouble Code 0305 points to a problem with the Exhaust Gas Recirculation Temperature Sensor. This sensor is a thermistor (a resistor with a value which varies inversely with temperature). The EGRTS is used by the Engine Control Module to test the EGR system operation. Since the signal from the EGRTS is not used for engine operation your car should run perfectly well despite having the Check Engine Light on.
Possible causes of DTC 0305 include ...
- harness or connectors (The EGRTS circuit is open or shorted)
- bad EGRTS
- malfunction elsewhere in the EGR system
The EGRTS may be tested with an ohmmeter.
- at "D" degrees F the resistance should "R" (in Megohms) should be ...
D = 32, R = 0.68-1.11
D = 122, R = 0.09-0.12
D = 212, R = 0.017-0.024
0306
Here's a video about EGR cleaning and replacement.
://www.youtube.com/watch?v=FB3l3Gw40nQ
http://www.autocodes.com/p0401.html
You may need to remove and clean the EVG tubes, EVG temperature semester and passageway, specifically EGR fuel tubing passageways. EGR cleaning is a maintenance self-service ritual that have is often done between 86,000 to and 110,000--- miles
Here's a link to the check engine light codes.
https://maxima.org/forums/4th-genera...ere-first.html
0302
Diagnostic Trouble code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- The electrical harness or connectors (valve circuit open or shorted)
- The EGR valve is stuck closed
- Weak or dead battery
- The EGR passage is clogged
- Faulty EGR temperature sensor circuit
- A leak somewhere in the exhaust system
The EGR Volume Control Valve may be tested with an ohmmeter. Disconnect the electrical connector. Looking at the connector half which is attached to the EGRVCV with the latch at the 12 o'clock position you will see two rows of three terminals. The top row is numbered 1-3, right to left. The bottom row is numbered 4-6, right to left. Measure the resistance between these terminal pairs:
2 1
2 3
5 4
5 6
... all resistance values should be 20.9-23.1 ohms at 68 degrees F.
Reconnect the EGRVCV connector halves. Turn the ignition switch ON OFF repeatedly. Verify that the EGRVCV shaft moves smoothly forward backward according to the ignition switch position.
The Exhaust Gas Temperature Sensor may be tested with an ohmmeter. The specifications are ...
- at 32 degrees F, 0.68-1.11 Megohms
- at 122 degrees F, 0.09-0.12 Megohms
- at 212 degrees F, 0.017-0.024 Megohms
0305
Diagnostic Trouble Code 0305 points to a problem with the Exhaust Gas Recirculation Temperature Sensor. This sensor is a thermistor (a resistor with a value which varies inversely with temperature). The EGRTS is used by the Engine Control Module to test the EGR system operation. Since the signal from the EGRTS is not used for engine operation your car should run perfectly well despite having the Check Engine Light on.
Possible causes of DTC 0305 include ...
- harness or connectors (The EGRTS circuit is open or shorted)
- bad EGRTS
- malfunction elsewhere in the EGR system
The EGRTS may be tested with an ohmmeter.
- at "D" degrees F the resistance should "R" (in Megohms) should be ...
D = 32, R = 0.68-1.11
D = 122, R = 0.09-0.12
D = 212, R = 0.017-0.024
0306
Here's a video about EGR cleaning and replacement.
http://www.autocodes.com/p0401.html
You may need to remove and clean the EVG tubes, EVG temperature semester and passageway, specifically EGR fuel tubing passageways. EGR cleaning is a maintenance self-service ritual that have is often done between 86,000 to and 110,000--- miles