viper 5901 shuts antenna off

Vehicle Toyota MR2 1991 Automatic Security System: Viper 5901 I'm contacting you pros here since you do know about the Viper 5901 system more than any other people. I have installed 4 of these systems already with various extra features commanded by the Aux features. The latest Viper 5901 module I got, has 4 aux, not the 3 the others had, and the wire harness was a little different, it had the old RSin and RSout bundles integrated into the old H2 wire bundle. Here's the issue the system works perfectly while the car engine is not running. As soon as the engine is running, the system does not recognizes the remote control signal at all, regardless if the vehicle was turned on by RS or by key. The problem only occurs while the engine is running, as soon as the engine is turned off everything goes back to normal and all features function perfectly. I have never had this type of situation and cannot find a solution. I do not have a Bitwriter, before I spend money on it, I want to make sure I tried all possible solutions. Is like if the system turns off the antenna if the engine is running. Any help you can provide me will be greatly appreciated. I'll post problem and solution in this Forum post once this issue is resolved. Check my older posts for installation recommendations for a 2005 Toyota Tacoma. Thank you.Always test. When in doubt, read and study. If still in doubt, read some more. If that don't work, don't do it then or your burn everything... a Chef

You may be experiencing interference from an ecu or another blackbox while the engine is running. Check to make sure that the ground is making good contact. Make sure the 5901 module is not mounted to any ecu type module. Try shifting the position of the module and/or antenna.This information is provided only as a reference.

All circuits should be verified with a digital multi-meter prior to making any connections.

From another response I sent: I use the auxiliary features for other stuff like fuel pump kill, or unlock doors, lock doors etc. even when the engine is running with the key in the ignition. This vehicle does not have key-sense. I installed the IG1 wire to the 2 Ignition wires on the car, I had originally the Viper on-board relay for IG2, but me thinking that was the problem I simplified the install to go with IG1 only (H3/1), and tried to use the remote with the engine running and that didn't fix my problem. I have relocated the module and antenna, not work either. I do notice that on my Installation sheet H3/1 is listed as (+) Ignition 1 input/output, on the old sheet it was listed as Ignition 1 output (also ignition sense input), Could it be that the module is getting a signal back from the IG1 (H3/1) wire and somehow interpreting it as to shut down the antenna? I remember placing a diode on the wire that went to the Xk05 on my 2005 Tacoma to prevent feedback. I know that on Toyota you cannot use the factory remote if the engine is running to unlock the doors etc.. I'm thinking on putting a diode on the IG1 (H3/1) wire to prevent input and see what happens. What you all think? Thank you.Always test. When in doubt, read and study. If still in doubt, read some more. If that don't work, don't do it then or your burn everything... a Chef

You dont want to put a diode on the IGN1 wire at all. the alarm needs to see ignition on during start up and while alarm is armed, etc.  They changed the wording in the manual but it all means exactly the same thing. You should also never use the IGN1 output to power 2 different ignition wires without using a relay. this will cause many problems with the system as well as the car. It sounds like either an IGN wiring issue or a defective brain to me. What happens with the functions of the remote while it is remote started, no key in the ignition. Does it work then? I'm wondering why you need the remote to work when the car is started with the key?

I'll switch back the on-board relay to function as IG2, I left all connections ready (just in case). I'm starting to consider that the alarm brain has problems. Unfortunately for me DEI will not merit their Warranty, since I'm not one of their dealers. The reason I need the remote to function while the car is running with key in IG-Switch are the following: to use the remote start feature to exit the car and leave the engine running while short trips, to activate the lock/unlock using the aux (In case I left the key in and doors locked), To activate a fuel pump kill in case of unauthorized access to the vehicle (i.e. carjack), and to be able to use the remaining aux for other stuff not yet contemplated. I always separate the remote from the key while in the vehicle so I have total access the my alarm configuration regardless if the key is in the IG-switch. I emailed DEI asking if there might be a setup option that can be programed to the module to by-pass the antenna if the car is running, but as usual they have not replied. I have done this same alarm install on 3 vehicles already (2004 Toyota Sienna, 2005 Toyota Tacoma, 1994 Toyota 4Runner, and now the 1991 MR2). The only difference I did notice was that the module I got for the MR2 looks different than the ones used in the other vehicles, so they (DEI) did change its design. So I cannot switch modules with the other cars to see if run into the same problem. Thank you on the advise regarding the diode. My last option is if there is something that has to do with the programing itself. One thing I'm very disappointed is the lack of customer support from DEI for non-dealer installers. My last question is could there be a programing feature associated with my problem? Thank you.Always test. When in doubt, read and study. If still in doubt, read some more. If that don't work, don't do it then or your burn everything... a Chef

What do you mean it does not recognize the remote? Do you mean you cannot control lock and unlock or what? How do you have everything wired up?

I'll post the wiring when I get access to the file. I'm certain I wired everything appropriately. The remote sends a signal but the console does not respond, only while the engine is running. There might be 1 of two at this point, either the console is messseup, or I somehow programed it to bypass the remote while engine is running.  I did notice that while programing the features I could access more features than those listed in the programing instructions, e.g. Menu 2 is supposed to have like 16 or 17 options, and I was able to get 19 chirps like if there are 19 options in menu 2.  I'm wondering if there are hidden programing features in this system, not listed in the installation sheet. Can someone check if with Bitwriter you can set the system to bypass the remote somehow? at this point I might just have to suckit up and use it that way, until I can get enough $ to get a second console to replace the faulty one. Thanks.Always test. When in doubt, read and study. If still in doubt, read some more. If that don't work, don't do it then or your burn everything... a Chef

How did you ground both systems? If you used an existing ground point try relocating them. It is usually a bad idea to use pre-existing grounds since they can carry electrical noise from other components.This information is provided only as a reference.

All circuits should be verified with a digital multi-meter prior to making any connections.

the viper is grounded at a standalone new location directly to the vehicle subframe. Not sure what you mean by both systems? This vehicle does not use key-sense. Thanks.Always test. When in doubt, read and study. If still in doubt, read some more. If that don't work, don't do it then or your burn everything... a Chef

sorry was thinking of something else while responding to this thread. But the ground question was meant for you. Where did you install the antenna? Also check for kinking of the antenna wire.This information is provided only as a reference.

All circuits should be verified with a digital multi-meter prior to making any connections.