4015V starts truck but immediately stops

I am struggling with a viper 4105V install in my 2007 Chevrolet Silverado Classic (V6 with auto).   I am also trying to use a flashlogix FLCAN module (the fourth one is on its way from Crutchfield so that's another story in itself). The truck starts when prompted by the remote but just runs for a second or two and cuts off. It does this three times and gives up. There are no flashes or clicks from the viper when it ends the cycle. Doing the diagnostics, its complaining about the tach signal (getting three flashes) but I have the tach hardwired to the instrument cluster (white wire at A5). The connections are all soldered correctly. It appears it is doing the tach learn correctly (red led flashes and then goes steady after a second or two) so it must be seeing the tach signal, right? When I disconnect the tach wire, it does the same thing under virtual tach (starts, then immediately shuts off). I've spent hours and hours on the phone with multiple techs at Crutchfield but have still not got this sorted out. I'm on my second viper unit (thought maybe the first one was bad). We tried to increase the crank time thinking that maybe the tach signal was a second or two late to latch the run function but manually programming it in didn't seem to increase the time so I don't know if we were doing it correctly. I've not yet gotten an FLCAN to work properly- they sent two with the wrong program and the one that was right would not do the final programming step to initiate BUT, I'm doing this with the key in the ignition, so the FLCAN should be out of the equation anyway at this point. I'm tempted to get the bitwriter to see what I can find in the Viper programming but would hate to throw more money at this if I can't make it work. Anybody seen this before or have any ideas? Thanks.

Did the FLCAN program ? Is it in d2d or hardwire mode ? Try disconnecting the Viper's brake input wire and the do a remote start and see what happens! Also the LED is supposed to turn solid when it learns Tach signal and not flash .triniforever

Did you test the tach wire for the proper reading?When all else fails, Read the Instructions

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The FLCANs are being programmed by Crutchfield. I can't remember if I am setting the program to data mode or hardwire but neither mode has worked. I can change the installation mode selection but have not yet gotten one with the correct program loaded that allows me to successfully complete the final module programming procedure (with the ignition sequence). We did disconnect the brake switch wire but it did not correct the problem. The brake pedal is also cancelling the start sequence when pressed and I checked the function with my multimeter.   IIRC, when the brake wire is disconnected it does not allow the start sequence to initiate. As far as the tach learn, it is working correctly- start he truck with the key, within 5 sec, press the valet button. After 3 seconds the LED lights constant when the tach signal is learned.... Release the valet button.

smokeman1 wrote: Did you test the tach wire for the proper reading?

I did put my meter on it (fluke 787) and tried to measure mA but didn't get anything. I haven't used the meter for anything but voltage and resistance for the last 15 yrs and I think my fuses on the amp meter are bad. I'll either try to get a couple fuses tomorrow or use the cheapo meter at work and see if I can get a reading.   The truck has a factory tach that is working and I am pulling my tach signal off what should be the correct wire. I've got the signal wire soldered correctly as well. Still leaves the question, if it is not seeing the tach signal, why isn't it switching over to virtual tach?

i would try setting it to virtual tach. also i believe the 4105 auto start brains do not pick up tach through d2d not 100% on that though. if it is the brake wire shutting it down you would get feed back from the auto start braing.

To measure tach set the meter to 20VAC

How do I set the tach over to virtual? Can I do it without the bitwriter? I thought if it didn't see a hardwired tach signal, it would automatically revert over to virtual. On Remote Start Diagnostics, I am definitely getting 3 flashes, "low or no RPM, low battery (voltage and virtual tach modes).

Look at the sheet of paper you get with the unit. It explains how to perform nearly all the programming without a bitwriter.

howie ll wrote: To measure tach set the meter to 20VAC

I am getting around 6.0 V on the tach wire but it is not fluctuating with RPM. Again, I have the factory tach in my instrument cluster and it is working correctly. I was thinking I perhaps had used a bad wire for my tach signal and was maybe going to pull the cluster (again) and measure on the wire itself, but if I am getting a voltage reading, the wire must be OK. I thought the tach and speedo were both DC stepper motors. Maybe they are and the signal conversion is internal within the instrument cluster circuit board?