ECU code problems. Can you solve?
Thread Starter
Senior Member
Joined: Feb 2003
Posts: 397
ECU code problems. Can you solve?
Let me first say that a couple of months ago my gas milage started getting pretty bad, like 240 a tank. So I assumed it might be the knock sensor. I checked the ECU and I indeed was getting the 03 04 code. So I bought a knock sensor, but I haven't installed it yet since it's been so damn cold.
Anyway, I'm driving back from work last night and my check engine light goes on. I check the code and it's an 03 02 - which is "EGR system hi/low flow". First of all I have no idea what that means, but I reset the ECU and the light didn't come back on last night or this morning. But what I thought was interesting is that when it was giving me the EGR code it wasn't giving me the 03 04 Knock sensor code. So now I'm not exactly sure what's going on. Any clues??
Anyway, I'm driving back from work last night and my check engine light goes on. I check the code and it's an 03 02 - which is "EGR system hi/low flow". First of all I have no idea what that means, but I reset the ECU and the light didn't come back on last night or this morning. But what I thought was interesting is that when it was giving me the EGR code it wasn't giving me the 03 04 Knock sensor code. So now I'm not exactly sure what's going on. Any clues??
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
Check your ecu again in a few days, the knock sensor code should be back.
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
Check your ecu again in a few days, the knock sensor code should be back.
Thread
Thread Starter
Forum
Replies
Last Post
litch
4th Generation Maxima (1995-1999)
123
Jan 4, 2024 07:01 PM
Kyle Lee Cleveland
6th Generation Maxima (2004-2008)
1
Sep 28, 2015 09:01 PM