Have 2 codes while trying to get my new to me car inspected. The Reset Valve code popped up so I cheked the VVt valve (applied power and ground and I heard it click) Cleared that and drove it and then the 25 code came up (p0171) when I got to the inspection place. Smoke tested the vehicle and found a small hard hose from the intake to the black box under the intake had broken. Compressor, alternator, ps pump and bracket removed to get to it. Changed the oil when I first got it but that damn code 61 keeps coming back. I see it ties into the ignition coil red wire so I assume that the ground is provided by engine management center. Does anyone know how to check if it is getting the correct power and ground and when should it? Im trying to avoid buying one new only to have the same thing happen.

 

I tested the VVT seprated from the engine. Even though there was an audible click, the valve showed no movement. I was getting a ground signal and a batt signal from the wires in the connector when the engine was running. I have ordered a new VVT. I will update when I get it in. The dtc 25 (p0171) did not return so far.

 

Ok here is an update. I replaced the VVt sol and thought everything was good. drove it a bit and went to start it the next day and the damn light came back on. dtc 61. I am at a loss as to what to do now. I wonder if the previous owner replaced the t-belt without setting it properly.

 

It's possible that there is buildup / contamination in the pathway to or from the solenoid to the VVT. I believe (though can't be sure because I don't know the year of your S40) that there is a fine mesh screen in the base of the "valve body" that the solenoid plugs into, or one of the internal passages could be plugged. Or, it makes sense that the VVT pulley (again, not sure about your model year) itself is bad.

And yes, if the timing is a tooth off... (certainly worth verifying before going too deep on other possibilities).

 

I feel your pain. Been there done that. In the end I was faced with replacing vvt. It’s now been a full year and code is not back.

 

I checked the wires, inspected the plug sleeves, put it back together. Drove it and parked it a few times while monitoring the rediness codes. Started it today and no CEL. Took it to the inspection facility and it passed. No CEL on at the moment. Im hoping it was the vvt all along and it just needed to get some continuous driving in it. Now I just have to get an aftermarket radio kit and figure out why the AC turns off and on periodically and i can let the kid drive it.

 

Since it's an oil-driven mechanism, it could be that there's just enough debris / gunk in the system to make it flaky. If so, changing oil more frequently might "fix" the problem (not entirely, but maybe it'll work well enough to not throw a code).

Most times an intermittent A/C will be because of wear on the A/C compressor clutch. The gap gets a little too far for the electromagnetic clutch to pull it closed reliably. You can (carefully) test this when it's not engaging by giving the center of the clutch a little love tap with a rod of some sort. If the clutch then engages, you know you've found the problem. There are a number of ways to fix this that have been documented on the forum(s), including shims (external to the clutch) or disassembly and re-shimming of the clutch (a whole lot easier on the S40 / C30 / V50 than my previous V70 T5, which had the clutch running right against sheet metal).

 

The AC actually powers off. The ac on light switches to off for a second then comes back on. Ill look at the wiring diagram to see what controls it.

 

If the AC light comes on and off it’s either that you are low on R134 or that the pressure switch on top of the dryer is malfunctioning (not very likely).