Viper 5701 Remote Start will not stay running for over 15-20 seconds

Couple of things to try:

First, If this unit has been configured to "virtual tach", then during cranking, it looks at the 12V battery's cranking voltage, and then checks it again in about 15 seconds to see if the voltage is higher (meaning the vehicle is running). If not, it turns off the ignition circuits. This was really the only 15-20 second shutdown feature I could find in the installation manual. Maybe since the Prius doesn't use its 12V battery for "cranking" the starter (I don't think; I think it uses the hybrid battery), then the 12V battery (if that's what the sensor line uses) would not change voltage, and therefore it would perhaps shut down. (Just a possibility). You could test this theory using a meter to monitor the 12V line during cranking and starting. The other thing that might be happening is that since the hybrid battery voltage probably doesn't drop much at all during cranking, it's again not seeing a change in the 12V cranking circuit. In "Voltage" mode (as opposed to virtual tach) it does the same thing, but doesn't wait 15-20 seconds - it checks right after the cranking pulse, still looking for an increase in voltage. The usual solution to either of these problems would be to put it in tachometer mode (which requires a lead to the ignition circuits), but that's a problem too, since the gas engine doesn't come on immediately upon starting, or even within 15 seconds, necessarily, and so you'd have no tach signal!

My suggestion is to contact the manufacturer (directed.com) to see how in the heck to connect this on a Prius, or go back to the installer to have them contact the manufacturer.

Here is some other troubleshooting info that you can use to diagnose exactly why the last shutdown occurred. This was taken from the installation manual, a link for downloading this is:

http://www.directeddealers.com/manuals/ig/viper/N5202V_2008_02web.pdf

I think the error that would show for the scenario above might be the "3 - Low or No RPM".

Good luck!!

jayvee

Shutdown diagnostics
To perform shutdown diagnostics​

With the ignition OFF, press and

hold the Valet/Program switch.

Turn the ignition ON and then back OFF while ​

​

holding the Valet/Program

switch.
Release the Valet/Program switch.
Press and release the Valet/Program switch. The LED starts flashing to report
the last shutdown for one minute or until the ignition is turned on, as shown
in the following table:
​

​

LED Flashes Shutdown Mode
1 Runtime expired
2 Over-rev shutdown
3 Low or no RPM
4 Transmitter shutdown (or optional push button)
5 (+) Brake shutdown
6 (-) Hood shutdown
7 Timer mode/Turbo mode/Manual mode error *
8 Neutral safety shutdown
9 Low battery (voltage mode)
10 Alarm triggered **
11 Wait-to-start input timed out
*Timer mode error: Ignition is on or shutdown input is active when activating
timer mode.
Turbo mode error: Turbo mode is programmed off, engine is not on or shutdown
input is active.
Manual mode error: MTS mode not enabled.​

** Alarm was triggered during remote start sequence.

​

 

What bypass unit is being unit? Is the installation D2D or W2W?