Q45 "Door Open" message stays on.

[LCheung]

The message "Door Open" is showing on the dash and will not turn off even when the doors are closed. I tried pushing the switches in manually to see if there was a change and there wasn't. Actually the message doesn't stay on, what will happen is the car will read the door is closed intermittently and keep the message displayed and keep all the interior lights on. I went through the manual and came up that it could be the courtesy light relay or the "control unit," but the manual doesn't really state which is the control unit. Any help would be appreciated. Thanks!

The car is a 1992 Q45 non active susp. 84400 miles and the car is located in Seattle, WA.

[Q45tech]

Sagging door hinges and bad door switches both common.

[LCheung]

If it was sagging doors, wouldn't pressing the switches in manual remedy the problem?

-Leon

[Q45tech]

Common to change the dual contact door switch. Sagging doors make for intermittents.

[Q-less]

Did you get it fixed?

What was it?

[BAJA_Q45]

Did you ever solve the problem? I am now having the same problem. I went out of town for three days and left my 91 Q45 locked in the driveway. On the second day the alarm started sounding according to my unhappy neighbors and kept cycling on and off until the battery went dead. When I got home, I recharged the battery and now find that the interior lights are always on and if started the “Door Open” indicator stays on all the time. I have tested all of the door jam switches and left them disconnected so that they cannot ground, and yet the lights stay on. I can’t imagine the wiring harness grounding its self while just sitting in the driveway, but I can imagine a relay failing. Anybody know where I should look to find the problem?

[Jesda]

This may or may not be related:zerothread?id=62202

[BAJA_Q45]

I checked the hood switch and found nothing wrong. Besides, would the hood switch cause then "Door Open" indicator to come on and the interior lights? I'll check it again. Any other ideas?

[BAJA_Q45]

No Takers?

[DAEDALUS]

Not the hood. It has to be one of the door switches or the wiring to one of the switches. You assumed that the switch grounding itself would trip the error, but what if that isn't the case? What if the switch is normally closed, and a break in continuity is what trips it? Don't know for certain, but it's a possibility. Have you checked for a voltage to the switches with the key on?

[BAJA_Q45]

Not the hood. It has to be one of the door switches or the wiring to one of the switches. You assumed that the switch grounding itself would trip the error, but what if that isn't the case? What if the switch is normally closed, and a break in continuity is what trips it? Don't know for certain, but it's a possibility. Have you checked for a voltage to the switches with the key on?

There is no voltage to the switches; they are ground wires that are grounded when the door is open. When the door is open the switch button is extended and the switch is in its normal closed position permitting a path to ground. When the door is closed and the switch is depressed, the switch is open and the ground is interrupted. When the switch is unplugged and removed it is that same as when the door is closed. I have removed the three passenger door switches to eliminate them from the equation and the “Door Open” indicator remained on. I then tested the driver’s door switch, bypassing it and the light and “Door Open” indicator stayed on. The only possibility is a short to ground somewhere in the wiring harness or in the security system.