car won't start, rad fans come on when key is "ON"
 

I'm currently having a problem with my 05 MT that I'm hoping someone can help with.

It currently won't start, it cranks but it won't turn over. What's weird is that the when the key is turned to "ON" the radiator fans automatically come on. This leads me to believe its an electrical issue. I thought it might be a problem with my IPDM (when I looked at it there was some corrosion in some of the connectors from it getting wet) so I tried replacing that (swapped it out with a used one). That didn't fix the problem though.

Anyone have any ideas?
I was searching and saw someone with a similar problem mention it was their "fan control module" that went bad - where is this located?

I think you found the problem

How did it get wet?

Put the original one back in
Spend the money to have your trouble properly diagnosed by a dealer.

Never a good idea to just start swapping parts unless you are positive that those parts are defective and the root cause of the problem.

Just my $.02

Telcoman

Normally moisture will get into the Ipdm/er because there is a drain underneath the battery tray that will get stopped up. It will cause water to back up and the level will rise and get into the IPDM. Even if you do swap it the corrosion will need to be cleaned off of the connectors as well. You will have to take each affected pin from connector to clean corrosion from it or you still may have a bad connection with the new one. Hope this helps.

Yup infinitidude, that's how it got wet. I've gotten the "Vdc, CEL, limp mode" issue in the past so I knew my IPDM's days were numbered. Putting the old one back in wouldn't be beneficial because there was clear corrosion going on, the one I put in was mint and I know it was working when it was removed from the other car.

I'll try doing a more thorough job of cleaning the connectors, I cleaned them when I swapped it but I was rushing so maybe you're right and it's just not making a connection. Getting the IPDM out is pretty painless so it's worth a shot. I like trying to fix issues myself before giving in to the dealer.

Check ECU connector (after disconnecting battery). Could be water in there. If you've messed with the grommet (e.g. for aftermarket audio power wire), then you may not have sealed it up very well. Fans will come on if ECU is not responding.

Do you have any codes?

I had the same problem, but it turns out I tried starting the car too many times with a key that had lost its program. This put the car into security mode. I had to go to the dealership and have the car relearn the key. Also check all the wires going into the ECU harness connector, I had one back out which caused some headache as well.

No I'm not getting any codes. When I connect my scanner/reader to it I just keep getting an error message saying it can't connect. This leads me to believe its my ECU as rcdash mentioned above. Hopefully it's just a connection issue and my ECU isn't fried or something. I've been swamped with work so I haven't had time to touch the car for a couple weeks but my next step is to check the connections to the ECU when I get some time.

Nicck6 - were you getting any codes when you were having your security issue or did it stop connecting like mine?

J_Burma, yes I was getting a code, I can't remember the name for the life of me, but it was an acronym like CANN. Once I had the key reprogramed to the car and the ECU wires correctly plugged in, it fired up.

Well I got my problem fixed (for now anyways).
As I mentioned earlier I replaced the IPDM because it had some bad corrosion and was had acted up in the past. What I didn't do was a thorough enough job of cleaning the connectors from the harness which also had corrosion on them.

Using a technique I found online - I let them soak overnight in a vinegar solution to eat away the corrosion (the vinegar is acidic enough to attack the corrosion but weak enough to not damage the coatings on the connectors). Following this I soaked them for a while and rinsed them in a solution of water and baking soda to neutralize the vinegar. I then liberally sprayed them with electrical contact cleaner and gave them plenty of time to dry.
This all took a few days because I could only submerge and soak a couple connectors at a time due to the space and orientation of the harness.

After doing all this, I reconnected everything and the car fired right up and is running normal again. Hopefully it lasts. We shall see.

Thanks everyone for your input.

Rad fans come on cuz yer car is rad, man.

Same problem, unexpected issue.
 

I'm having the same exact problem but it was just the CRANKshaft position sensor, it's under the motor where the engine and transmission meet, did not expect a sensor to cause such weird issues but I fixed it and it's running great. Like if your still looking at this old website in 2019.

Your car being an 05 does not have a fan control module. If the fans are running with key on check and see if security light is on solid. Check fuse labeled Eccs in ipdm. Sounds like it may have a bad ECM.

^I'm very grateful to see you're still hanging around...…..

Mine Does the same and more
 

My random problem is; fan runs all the time, tach & temp display 0, Slip light iluminated, VDC Off light illuminated, shifts like it has a shift kit in it, stays in gear too long wont upshift correctly. After test drive car would not start. Left car for 1 hour tried again car started right up, no problems, vdc button works, did not go for test drive.

The hot start issue is probably a failing starter, VDC problems can be many things but the easiest to fix possibility is simply low brake fluid.

Hard shifting however is possibly a concern. It MIGHT have the Transgo shift kit installed, or it might have a lot of friction modifier added to the tranny fluid, or the transmission might be on it's last leg.