Remote door opener fails in cold weather

[Kencard1]

The remote for my 1999 Infiniti I30 will not open the doors when the temperature is 35 degrees or colder. After driving the car or when the temperature is above 35 degrees the remote opens or locks the doors with no problem. I have changed the battery in the remote but this didn't solve the problem. Anyone have any ideas ?

[seyath]

I'll be easy on you because it is your first post ;-)I moved this to the I35 section because you would get the most help here. You had posted this in the Spanish section. I'm sure someone will be able to help you now.

[Kencard1]

Thanks for your help

[audtatious]

The only thing I can think of would be to pop the door panel off, peel back the moisture barrier, then use some good lube to grease everything back up.

Is it just the drivers door or all doors?

[Kencard1]

When I have the problem it is with all doors and the trunk. When the weather is 35 or below I'm unable to lock or unlock the doors and trunk. I can manually lock and unlock everything using the key. Any other ideas ?

[audtatious]

Hmmmm. That makes it some sort of electrical problem within the security system.

Remote functionality is handled via the Multi-Remote Control Unit, which interfaces with the Alarm Unit and the Time Control Unit.

At this point, I have looked for related information or people having similar problems, but I'm not finding anything for a 4th gen. Some 3rd Gen's have had similar problems where theirs won't work at all unless it is really hot out. Their solution is to resolder broken solder joints or mess with the connectors of the Time Control Unit.

[Kencard1]

Thanks for your analysis of my problem. I think you are right and either the Multi-Remote Control Unit or the Time Control Unit is faulty.

Are these units accessable to an amateur or do I need to bite the bullet and go to the local Infiniti dealer ?

[audtatious]

Interesting. I started going through diagrams again and I wonder if I was looking at the wrong year.

The 1999 models refer to the BCM (Body Control Module) and not a Time Control Unit. The BCM is located behind/below the radio (must remove radio and ash tray). From what I see, the LCU's (Local Control Unit which is each doors window/lock switches) communicate to/and are slaves of the BCM. When nothing is happening, the BCM "goes to sleep". When key is inserted, it wakes up and wakes up the slave LCU's.

The Multi-Remote Control Unit (LCU05) is located in the trunk on the right side and has a direct data line to the BCM. Signals via your key fob are received via the MRCU which, in turns, wakes up the BCM.

So, I would check the MRCU first, then proceed to the BCM.

[Kencard1]

I found the MRCU and removed it. I cleaned the terminals and made sure that the wires were not frayed. I hope this solves the problem. It will be a couple of days before we get cold weather again and I'll let you know if this was the problem. If it isn't I'll check out the Body Control Module before replacing the MRCU.Thanks for your help.

[audtatious]

Not a problem. Let us know how things turn out or if you need additional help with it.