Remote Keyless Entry mess

[FatherTime]

I knew the RKE wasn't working correctly when I bought this car, but wasn't really all that concerned about it. When anything ever works, (rare), it works for only a couple minutes, then stops. It seems like it's completely random and intermittent, and, the rear door locks never worked at all. I did take it to a mechanic, and he identified an issue (open circuit) in the master door switch. I put in a new switch and not much change, but the mechanic noticed a clicking noise in the dash when activating the power door switch that wasn't happening before the new switch. That led him to think the problem was probably electrical, so he started rummaging around in the fuse box area, then came to the conclusion that my problem was likely in the computer. At that, I gave up. Not going to spend that kind of money.

Today, I noticed that the front door locks were both working exactly as they should, using either the key fob, or the door switches. That's never happened before. I spent a couple minutes locking and unlocking the doors to see if it was going to stay working, and...nope. Went back to the previous condition. I"m probably wrong, but I would think that it would be obvious what the problem is. Does this sound like a problem in the computer module? I have no idea.

[joatmon]

Starting with a disclaimer, I don't know about the 09's or if this is in any way useful to troubleshoot your problems

In the 03-08's there was an electrical module that was called the Integration Relay, or Multifunction module, depending on Toyota or GM. It was a small box snapped onto the under dash fuse block that controlled the electrical door locks. Took inputs from the door switches and the remote receiver, sent signals to the door lock solenoids. a thread that talk about it more for an 05 is viewtopic.php?f=18&t=46751

No telling how similar your 09 is to that, but perhaps there is such a module in your car, and perhaps it might be whats not working right. That's a couple of nested perhaps's, so maybe useless info. However, if there is such a thing in your 09, it would easier and cheaper to replace than what I think of as the car computer, sometimes referred to as ECM or PCM. But I don't have any wiring diagrams for an 09, so can't say how to find or check out such a thing, if it exists.

[FatherTime]

Starting with a disclaimer, I don't know about the 09's or if this is in any way useful to troubleshoot your problems

In the 03-08's there was an electrical module that was called the Integration Relay, or Multifunction module, depending on Toyota or GM. It was a small box snapped onto the under dash fuse block that controlled the electrical door locks. Took inputs from the door switches and the remote receiver, sent signals to the door lock solenoids. a thread that talk about it more for an 05 is viewtopic.php?f=18&t=46751

No telling how similar your 09 is to that, but perhaps there is such a module in your car, and perhaps it might be whats not working right. That's a couple of nested perhaps's, so maybe useless info. However, if there is such a thing in your 09, it would easier and cheaper to replace than what I think of as the car computer, sometimes referred to as ECM or PCM. But I don't have any wiring diagrams for an 09, so can't say how to find or check out such a thing, if it exists.

I believe the mechanic that looked at the problem said he went over the electrical diagram and said there was no relays, which I guess is why he started pointing at the computer.

[jolt]

Attached are the wiring drawings for the door locks on a 2009 Corolla, which should be close to the same as the 2009 Vibe. Some wire colors may be off but the same basic wiring is happening for the Vibe. As shown there is no relay in the door lock system. Switch and lock motors inputs and outputs are controlled by the Main Body ECU in the drawings.

Do the locks work every time when using the key in the door handle lock for both front doors (not using the FOB)?

ECU's, for the most part, do not work some times and then work other times. I would say you have a bad connection or a broken wire in the system. The only way your going to find it is to start checking all the related wiring with a meter.

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[FatherTime]

Do the locks work every time when using the key in the door handle lock for both front doors (not using the FOB)?

ECU's, for the most part, do not work sometimes and then work other times. I would say you have a bad connection or a broken wire in the system. The only way your going to find it is to start checking all the related wiring with a meter.

The front doors always need to be locked/unlocked separately using the key.

So what you're saying is that, the intermittent nature of the problem points more toward a wiring problem as opposed to a faulty ECU? If so, that's what I was thinking, but the mechanic that looked at it wanted to blame the ECU. He stated that they can act erratically. I'm no electrical engineer, but that didn't make sense to me. Plus, something had to cause the main power door switch I replaced to go bad. (the open circuit in the switch he found) Maybe a short in the wiring somewhere?