Hello all!
I have a 97 SE 5-spd with 56K. My light came on (wife was driving) Thanks to your info, I simply checked the codes and got 7-5 and 9-3. Had done this on my F-150, so I wasn't concerned. So I go to Nissan and the service kid wants the $90 diagnose fee. So I moved on to the parts guy and ask for info on the EVAP canister vent control valve. Where is it? Is it a warranty item? "No, not after 3 yr 30K" he says, and points out the part atop the manifold. $59. So I go back out to service and the mngr (slow day, I was getting lots of help) says no it's in back, behind the canister. "Just stuck open, OK to drive a short time". So I go home and pull this thing. There's nothing to it. Is this the right part? How do I check it? What does it do? Should I clear the codes and see if it happens again?

 

You will find instructions to do a DTC readout and reset
the Check Engine light at:
http://vbxmaxima.8m.com/ecu.html

The DTC "translations" are found at:
http://vbxmaxima.8m.com/ecudecoder.html

When you get the four-digit Diagnostic Trouble Code readout, post it here.

 

Sorry, I got two codes, 0705 and 0903.

 

Diagnostic Trouble Code 0705 points to a problem with the Evaporative Emission Control System.

This malfunction is detected when the EVAP control system has a leak or the EVAP control system does not operate properly. (EVAP = EVAPorative emissions.)
Possible causes include...
- incorrect fuel tank vacuum relief valve
- incorrect fuel filler cap
- fuel filler cap vent remains open or fails to close
- foreign matter caught in fuel filler cap
- a leak in the line between the intake manifold and the
EVAP Canister Vacuum Control Valve
- foreign matter caught in the EVAP CVCV
- leaks in the EVAP canister or fuel tank
- leaks in the EVAP purge line (pipe and rubber tube)
- EVAP purge line rubber tube bent
- blocked or bent rubber tube to EVAP control system pressure sensor
- loose or disconnected rubber tube
- EVAP CVCV and circuit
- EVAP Canister Purge Volume Control Solenoid Valve and circuit
- absolute pressure sensor
- tank fuel temperature sensor
- MAP/BARO switch solenoid valve and circuit
- blocked or bent rubber tube to MAP/BARO switch solenoid valve
- O-ring of EVAP CVCV is missing or damaged
- water separator
- EVAP canister saturated with water
- EVAP control system pressure sensor
- refueling EVAP vapor cut valve
- ORVR system leaks

 

Holly Cow! I was thinking the code 0903 had narrowed it down to the EVAP Canister Vent Control Valve. Isn't this in back of the box just behind the left rear wheel? And how do I verify it is working properly?

 

Diagnostic Trouble Code 0903 points to a problem with the EVAP Canister Vent Control Valve. EVAP stands for EVAPorative emissions control.

The EVAP CVCV is located on the EVAP canister (underneath the vehicle near the left rear tire) and is used to seal the canister vent. It has one hose connection and one two-wire electrical connector. The solenoid in the EVAP CVCV responds to signals from the ECM. When the ECM sends an ON signal, the coil in the solenoid valve is energized. A plunger then moves to seal the canister vent. The ability to seal the vent is a necessary part of the diagnosis algorithms for other evaporative loss system components. This solenoid valve is used only for diagnosis, and usually remains open. When the vent is closed, under normal purge conditions, the evaporative loss system is depressurized allowing "EVAP Control System (Small Leak)" diagnosis. Since this part is used only for brief emissions tests the vehicle will usually start and run well despite a Service Engine Soon warning light on the dashboard.

The EVAP CVCV may be bench tested. Remove it from the vehicle (one hose, one connector, two bolts). Verify that air may pass freely through the valve. Then use a pair of fused test leads to apply 12 volts to the terminals to energize the solenoid. Verify that air does not pass freely through the valve. If the CVCV fails these tests, try cleaning it with WD-40 and compressed air. If this fails to free it up, replace the valve. When you install a CVCV (the original or a replacement) always use a new O-ring.

 

Thanks alot Daniel. I must have been looking at the wrong component if the cvcv has wires too it. The part behind my canister just has two hoses on it. One from the canister, the other open to atm. But no wires. Seemed like a strange part, as I could blow thru both sides. Thought it would be like a one way or something. I will have to look tonight for the component you describe. Sure seemed like that was all that was there.

 

DTC 0705 may be considered a "jackpot" code because it points at so many things. I expect that when you do whatever repairs are necessary to clear the 0903, the 0705 will also go away.

 

Oh...OK I found the cvcv, it's in front of the canister. I was looking in back. The bolts were pretty tight, so I wd-40 them and will probably attack it tonight. Can I get it out just by itself or should I pull the box down? A little close in there. Can you tell me exactly how the connector comes apart? Just pull? or are there catches?
Thanks for all your help. The self diagnostics on today's cars are so cool! From the list of the first code a guy could spend a week trying to figure it out. Suppose there's a chance this won't cure all my problems, but I have confidence (and the $90 I avoided spending to check the codes!).