head scratcher, fans and reverse lock out...
#1
head scratcher, fans and reverse lock out...
So the car has been running perfect forever. Yesterday I start it up (cold) and immediately the first cooling fan comes on then the next. I then try to back it out of the garage and the reverse lockout is engaged. With the engine off I can overcome the spring so I know its not mechanical. No SES light but I will check with a scanner soon. Fuses under the hood seem fine. I am just trying to find a place where both of these electrical systems come together because they must be related, both occurred at the exact same time? I do have a manual override switch for the fans that I installed like 10 years ago with lights so thats how I know the fans came on. I checked the connections for that switch and they look fine. Plus the switch is working as it should, if the fans come on without me turning on the switch the lights come on to just let me know, so I think the problem is ahead of the switch anyway. Ideas?
#2
Re: head scratcher, fans and reverse lock out...
Maybe get it scanned, PCM activates fans for certain DTC's , reverse lockout is activated when PCM sees vehicle speed (VSS) 5 MPH or greater. May be a VSS error ?? The lockout solenoid is feed +12v ignition from a fuse and needs a ground from the PCM to activate. So a bad/blown fuse or open connection (missing voltage) would prevent activation. Only a short on the PCM activate line to ground would activate the solenoid. Bottom line looks like the PCM saw something abnormal that cleared. The DTC's if any should have been stored..
#3
Re: head scratcher, fans and reverse lock out...
The reverse lockout solenoid is fed from Fuse 10 (Engine Sensors) in the under hood box. That also supplies the MAF sensor, heaters in O2 sensors, and skip shift solenoid. The failure of any of those except the reverse lockout should set a code.
SES light working?
SES light working?
#4
Re: head scratcher, fans and reverse lock out...
Wow, some of this is over my head. Fuse 10 is fine, and the SES light is not on but is working. I do have a skip shift eliminator on the tranny that has been there over 10 years. Should I try taking it out? I have a buddy with a scanner, will scan it this weekend. Thanks for the input guys-
#5
Re: head scratcher, fans and reverse lock out...
Well code read 0500, speed sensor, which makes sense. But after unhooking the battery for a few hours both problems are fixed, even after several restarts. Who knows.
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