Cruise Control keeps blowing the fuse
08-14-2011, 11:56 PM
#1
Rennlist Member
Thread Starter
Cruise Control keeps blowing the fuse
I never had any problems with my cruise control until recently, after doing a bunch of work on my car. I installed M030 springs and Bilsteins myself, and the dealer did the alignment and also flushed the brakes/ABS/ABD circuits.
Now, every time I try to engage the CC by pushing the stalk, the fuse blows instantly. I know the short isn't in the brake system because the fuse never blows until the moment I push the CC stalk forward. The cruise was working fine before all the work was done so I'm stumped as to what may have gotten messed up.
The brake switch, clutch switch, steering column switch and cruise ECU under the seat all have not been touched, so that makes me think the short must be in the area of the actuating module behind the engine. Since I had my hands and a ratchet back there on both sides fastening the top mounts of the rear struts during the M030 installation, I'm guessing I hit something or yanked off a connector and now the circuit is shorted.
There's a great diagnostic procedure in the workshop manual to test the various components via the ECU connector using a multimeter, but since the fuse blows as soon as the circuit is activated, I assume performing this procedure is impossible. (edit: It just occurred to me that the procedure requires me to pull the connector from the ECU; if the short exists in the circuit downstream of the ECU, the fuse shouldn't blow during the procedure. I'll try it.)
Two questions:
1. Where exactly is the actuator module located in the engine bay? How do I identify it? I'll try to use an inspection mirror to see if anything looks amiss.
2. Any other ideas about where the short might be, if not at the cruise actuator?
Now, every time I try to engage the CC by pushing the stalk, the fuse blows instantly. I know the short isn't in the brake system because the fuse never blows until the moment I push the CC stalk forward. The cruise was working fine before all the work was done so I'm stumped as to what may have gotten messed up.
The brake switch, clutch switch, steering column switch and cruise ECU under the seat all have not been touched, so that makes me think the short must be in the area of the actuating module behind the engine. Since I had my hands and a ratchet back there on both sides fastening the top mounts of the rear struts during the M030 installation, I'm guessing I hit something or yanked off a connector and now the circuit is shorted.
There's a great diagnostic procedure in the workshop manual to test the various components via the ECU connector using a multimeter, but since the fuse blows as soon as the circuit is activated, I assume performing this procedure is impossible. (edit: It just occurred to me that the procedure requires me to pull the connector from the ECU; if the short exists in the circuit downstream of the ECU, the fuse shouldn't blow during the procedure. I'll try it.)
Two questions:
1. Where exactly is the actuator module located in the engine bay? How do I identify it? I'll try to use an inspection mirror to see if anything looks amiss.
2. Any other ideas about where the short might be, if not at the cruise actuator?
