Cool, thank you Belairbrian and 97greenstang. I checked today and I will be ordering some key fobs for my keyless entry

 

I have a new delimma today, my wife goes out to use car today and she says the door locks are not working. I just tried it and SOMEtimes it unlocks the driver side with driver switch SOMEtimes with the passenger switch, neither switch activates the passenger side. You go back a few minutes later and nothing works. I know it's not the fuse because the other thing the fuse controls is the trunk release, and it's working fine each time, help!!

 

Just looked at the schematic, and all door unlock/lock signals come from the remote/keyless entry module. Even when you use the door switches.

Essentially, when you press lock on either door it applies a ground to the module on connector c400 pin 4. Unlock applies ground on pin 5.

On the same connector pins 2 and 16 are the all dors lock output
pin 3 is drivers door unlock
6 and 16 are passenger door unlock.

c400 is a grey 13 pin connector on the module so I would start by checking it for security and cleanliness.

Then if that doesn't fix it I would check for good ground on pins 4 and 5 when the switches are actuated. If those are bad then it's in the switch side. There are 5 different connectors in that part.

If those were good I jumper 12 volts to the pins on c400 to verify the circuits on the output side of the module to test that part of the circuit. But I fixed aircraft electronics for 20 years and have the factory diagrams. You should probably disconnect the anti theft module if installed during this test.

Or you could just swap the module.

 

Wow, I'm going to have to read that over and over to understand. How could the locks work perfect for the last month or so, (since purchasing) and now that I do the programming for fobs, something happens.

 

it makes since when you look at the diagrams. Really it does. Is the behavior the same with the remotes?

Several possibilities as to why it suddenly showed up. One is the module just failed it happens. Another is it is just confused and would reset if it was allowed to sit awhile unconnected.

Another possibility is corrosion finally reached the point where it is causing problems on a connection or ground. Corrosion takes a while to accumulate till it causes problems.

Due to the way the circuit is designed a failed lock motor could cause your symptoms but that would require taking a door apart to test.

After thinking more about the symptoms it sounds like the module but I would test both sides.

Test the switch side by:
Disconnect the grey 13 pin connector form the remote entry module.
Connect a multi-meter set for ohms between a good chassis ground point and pin 4 of the connector.
Have someone press each switch to lock - the meter should show zero ohms (continuity) until the switch is released
Repeat checking pin 5 while pressing unlock.
If both test are good move on to checking the motors.

Testing the door lock motors:
Disconnect the gray connector from the module
Disconnect the anti theft module (just to protect it)
You will need 2 jumper wires and 12v to make this work
Connect a red jumper wire to the positive and a black jumper wire to negative.
Touch the wires to pins 6 and 18 on the gray connector. The passengers lock should actuate. Reverse the connections and it should reverse the lock.
Repeat the test with pins 3 and 16 to test the driver’s door lock

If that test is good, the module is faulty.

 

Let me know. How can I reset it? (Unconnect?)

 

I just also noticed you asked about the fobs, I didn't try, honestly, this is going to be a bummer, because they are wrapped as a Christmas gift and now they probably wont work. But the last time I used them, everything worked perfect. I don't even know where the module is, just the grey connector that you jump for programming.

 

the module is behind the black bracket where the gray connector is. Lock at the picture on the top of page 2. That's the bracket. The module is behind it. If you have a module on the front, that is the anti-theft module.

If you remove all the connectors and let it sit a while it should lose any "memory" it might have.

One other quick test, manually unlock both doors and see if they lock.

 

Are you saying leave unplugged, then I'd have to reprogram fobs? AND, do you mean by Manually, use the door switches on doors (while unplugged ????)

 

Yes, if you reset it it may loose the codes but I'm not sure. I've had a battery go completely dead and the key fobs worked. But I can't say for sure.

The manual thing was with everything connected, manually unlock the doors with the door *****. If they will close then the wiring on the output side is working. The same wires are used to lock and unlock. The module just reverses the polarity of the motor voltage.