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Intermittent door unlock

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Old 03-21-12, 05:00 AM
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BellevueES
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Default Intermittent door unlock

’98 ES300 will periodically trigger all doors to unlock, sometimes repeatedly at an even interval (approx 1 second perhaps 10 times). This only happens when the car is stopped and the driver’s door is open with engine off or running and will stop when the door is closed. When this happens, there is no beep as when the key fob is pressed. At times it will not repeat for days or weeks and can be very intermittent. My guess is that it is a logic module such as the door lock ECU, remote ECU, or Integration Relay and not a door switch or key switch due to the rhythm when it triggers multiple times (but it still could be a switch or wiring issue). Lack of repeatability makes trouble shooting difficult. Any ideas would be appreciated
Old 03-21-12, 05:29 AM
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BDSL
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Originally Posted by BellevueES
’98 ES300 will periodically trigger all doors to unlock, sometimes repeatedly at an even interval (approx 1 second perhaps 10 times). This only happens when the car is stopped and the driver’s door is open with engine off or running and will stop when the door is closed. When this happens, there is no beep as when the key fob is pressed. At times it will not repeat for days or weeks and can be very intermittent. My guess is that it is a logic module such as the door lock ECU, remote ECU, or Integration Relay and not a door switch or key switch due to the rhythm when it triggers multiple times (but it still could be a switch or wiring issue). Lack of repeatability makes trouble shooting difficult. Any ideas would be appreciated
Is the key still in the ignition switch when it happened?
If so, you might have a short on your power window switch somewhere.
Old 03-21-12, 06:38 AM
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01LEXPL
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Have you changed the battery.... ?
Old 03-21-12, 06:47 AM
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Do you have any aftermarket alarm system, immobilizer, or remote start installed?
Old 03-21-12, 07:59 AM
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BellevueES
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The key is still in the ignition. Next time the problem happens, I'll remove the key and see what happens.
I have no aftermarket items. The car is stock OEM
I have not changed the battery in the key fob. Main starting battery checks good. I'll install a new key fob battery...it's a easy and inexpensive to eliminate a potential problem.

In reviewing the system schematic, I'm suspect of the Integration Relay. Still looking for more ideas.
Old 03-21-12, 08:48 AM
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*I mean't FOB battery.
Old 03-21-12, 08:50 AM
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RealFixesRealFast on youtube had something similar. Hope this helps.

Symptoms

Diagnosis

Solution
Old 03-21-12, 01:17 PM
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BellevueES
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Great trouble shooting video on eratic door locks. My issue is far more intermittent, but I clearly need to rethink the input switches and find a way to test them. I don't have a lab scope, but disconnecting each individual switch could work...it's only time and I'm retired.
Old 04-10-12, 12:16 PM
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BellevueES
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Problem found after a hard failure.
Turns out that the plastic pushrod connector at the driver door handle failed. It wasn't electronic or electrical, but a mechanical linkage that was causing the driver door key switch to bind and trigger the unlock. After several months of being intermittant it had a hard failure. When it finally failed the drivers door handle would not open the door. Easy to find then and fix with a $4 part.
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