Hello everyone,

I got a 2005 2.2L 5-speed manual Saturn Vue. Ever since I got it, I've been having intermittent accelerator pedal issue. Before I thought it was something else. I'll give you a little background on this issue.

I got the vehicle in November 2015 as my college car. Initially when I drove it home I saw engine power reduction code along which check the engine light go on. I scanned the codes and I got APP/TP low signal voltage code. Immediately, I started throwing parts into it replacing both throttle body and accelerator pedal. They were at no cost to me so I thought I might as well take the opportunity to replace both. Throttle body had a lot of carbon build up. It seemed that the issue has resolved it self.

I drove the car for about six month before I got the same issue back. At that time I was in an advanced engines diagnostics class and we were going over throttle bodies and accelerator position pedals. I brought in my car so I can work on it and do a class presentation on it. At this point I kind of realized that the issue is happening every time it rains or snows heavy. What I decided to do is take a squirt bottle and set it on mist until the issue comes back on, because by the time I drove to class the issue resolved itself. Initially, we sprayed down my car in a wash bay with a hose, on the outside, and it seemed to set the code immediately. So we went and looked to see where the water was entering. We opened the hood and saw that there was a lot of water there and assumed the issue was under the hood. The following day is when we started to use the spray bottle. I squirted some water my throttle body wire harness and nothing. I sprayed around some other wires just to test everything, nothing. Then I noticed that my throttle body sits right over the ECM and the harness from throttle body goes directly to ECM, so I decided to take apart the ECM connector. I found out that there was a lot of dirt and moisture trapped under the plastic cover of the connector. I cleaned that off with an electronic cleaner put everything back together and it seemed to be fixed. I drove the car for 1 full year in rain, snow, and nothing happened.

Now, about 2 weeks ago I drove back to school from Fall break. About 5 miles from my apartment it started to rain heavily to a point where everyone had to drive bumper to bumper going at max 10 mph with blinkers on, visibility was non existent. At that point I noticed that I started to get leaks from the front doors' posts and from the overhead panel, no APP issue yet. A week later, I left my car where in non student parking and it was raining hard. I went to move my car to student parking and my car would not accelerate and have the engine reduce power light on and check engine light on, at the same time I had pile of water on the floor and in the overhead panel. I went and looked at my ECM and everything under the hood was dry. I had my car towed and when they lifeted the car, there was lots of water that was drained. I worked on it the following day and by that time there was no check engine codes nor the engine reduced power mode.

So, what I was wondering is this an issue with my sunroof drain or the seals? At the moment I am thinking it might be the sunroof drain but not 100% on it. I haven't really worked on it in class since the classes I am in now are automatic transmissions and hybrid electric vehicles.

 

I don't see how sunroof drains could cause an engine driveability issue, but it sure sounds like it might be related. Does this car have a BCM? If so, I'd pull the kick panel and check the connections on the BCM. Maybe water is building up in the A pillar and saturating it when it rains? IDK, I'm NOT a mechanic. BUT, I'd sure as hell check those sunroof drains before it happens again, if it were mine. At least you might stop the water from coming in during the next monsoon.

 

No it doesn't have a BCM. One thing I observed is that when I had the water issue, I saw the water stream on a wire that was going to accelerator pedal. My theory was that the sunroof drain is clogged so it over flows into the overhead panels and side pillars which then works its way through the dashboard and onto the APP wire.

 

I'm pretty sure that by 2005, every Saturn produced had a BCM, But let's put that aside.
Sunroof drain issues are terribly common on Saturns -- multiple model lines. Considering the age of all these vehicles, going 10+ years without a sunroof drain plug is actually pretty good, relatively speaking. I'm sure the same is true on other sunroof equipped vehicles.

If you see water literally hugging the insulation of the APP wire , I would venture to guess that is contributing to the APP reduced power mode.
For the water to get under the headliner, I believe it must come in ABOVE any portion of the door seal UNLESS the topmost part of the door seal by the sunroof drain is HIGHER than the headliner in that region. That will be a task for you to determine. I may be wrong. If I am right, then the massive amounts of water getting in cannot be coming from the front door seal.

That being said, unclogging those sunroof drains is the priority, both front and back if you are getting water in the back too.

Since whatever is clogging the drains is 10 years worth of fermenting scuz, do NOT try to blow it out with compressed air. It will only pack the material in there tighter.
Find a suitable stiff tool with no sharp edges on the end so that you will not rip the drain tubes and physically gently ream out each drain until water freely flows through each. Take your time, This can be a very frustrating task..

 

Yeh sorry, I do have a BCM and it is on the passenger side left kick panel. I got BCM and PCM confused, I don't have a PCM or I should say I have ECM which serves in place of PCM. I will try what you have suggested as soon as I dry everything out inside my car and when it stops raining outside, hopefully it won't get cold by then. Really appreciate the feedback. I know my car is leaking bott in the rear because my rear side trays get filled with water, most front pillars from the most top corner that connects the door to the windshield and again the headliner.

Thank you again, I will try to update when I find the issue.