Question about 1992 GMC Yukon
Door locks intermittently work.Will unlock but wont lock. Sometimes the actuators are sluggish to move to the lock position and other times show no attempt to move to lock position, but clearly have a draw on the battery (interior lights dim). I bought a relay to see if it made a difference but I am having trouble finding the relay location under the dash, at fuse box or under hood.
The relay or switch may be shorting, check other door lock controls for correct function, this will rule out relay and isolate the switch or rule out master switch and isolate relay.
Posted on Dec 12, 2015
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Posted on Jan 02, 2017
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DTC B3133 All Door Unlock Circuit High
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Aug 25, 2015 | Cars & Trucks
DOOR LKS fuse
Driver door lock actuator
Driver door lock switch
GMLAN serial data link
Keyless entry transmitter
Passenger door lock actuator
Passenger door lock switch
Remote control door lock receiver (RCDLR)
The DR LCK fuse supplies battery voltage to the body control module (BCM) for the power door lock system. The BCM supplies and monitors a reference voltage to the driver and passenger door lock switches through the door lock switch lock/unlock signal circuit. Each door lock switch receives ground at G300 which is also the ground for the door lock and unlock relays located in the BCM. When a door lock switch is placed in the lock position, the reference voltage is switched to ground and the BCM senses 0.0 volts on the door lock/unlock signal circuit. When a door lock switch is placed in the unlock position, the reference voltage is switched to ground through a 1.5k ohm resistor that is internal to each of the door lock switches and the BCM senses approximately 2.9 volts on the door lock/unlock signal circuit. The BCM interprets what position the activated door lock switch was placed in based on the voltage drop.
The BCM, upon receipt of a lock or unlock switch signal, will switch the appropriate door lock/unlock relay coil control circuit to ground causing the appropriate door lock/unlock relay to energize. With the relay energized, voltage is applied to the door lock actuator control circuit causing the door to either lock, or unlock depending on what command was received from the power door lock switch or remote control door lock receiver (RCDLR). When a power door lock/unlock relay is not energized, the switch contacts are normally grounded through the BCM which provides ground to the appropriate door lock actuator for the lock/unlock function being performed. The power door lock/unlock functions are performed by reversing the flow of voltage through the door lock actuator control circuits. The BCM has three internal drivers for the power door lock system. Driver door unlock, passenger door unlock and all door lock. This is done to isolate the driver door lock actuator so it can be unlocked separately from the passenger door. For additional information concerning keyless entry, refer to Keyless Entry System Description and Operation.
This is one you may want to take to dealer or some other ASE certified repair shop ! To do this right you need a Tech 2 scan tool !
Ignition ON, observe the scan tool Door Lock Switch parameter while using the driver and passenger door lock switches. The parameter should change from Idle to Lock and Unlock.
If the value does not change, refer to Door Lock Switch Malfunction.
Command the doors to LOCK and UNLOCK with the scan tool, the door lock actuators should LOCK and UNLOCK when changing between the commanded states.
If one or more doors do not LOCK or UNLOCK, refer to Door Lock Malfunction.
Aug 12, 2015 | 2009 Pontiac Solstice Convertible
A door lock cylinder switch unlock actuation.
A keyless entry transmitter actuation.
An automatic door lock actuation (Personalization function).
An automatic door unlock actuation (Personalization function).
A last door closed locking (LDCL) actuation (Personalization function).
Door Lock Operation
When the body control module (BCM) detects a transition of either of the door lock switches to the lock position, it switches the door lock actuator lock control circuit to voltage. Since the lock actuator unlock control circuits are at ground potential within the BCM, the door lock actuator motors transition to the lock position.
Driver Door Unlock Operation
When the body control module (BCM) detects a transition of either of the door lock switches to the unlock position, it switches the driver door lock actuator unlock control circuit to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the left front (LF) door lock actuator motor transitions to the Unlock position.
The driver door lock actuator unlock control circuit is a dedicated control circuit used only for the driver door lock actuator motor. This is done so that the driver door may be unlocked by itself using a keyless entry transmitter or an automatic door unlock function (if programmed).
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.
A factory scan tool would help for checking inputs from the door switches to the BCM ! You could do it with out scan tool , a lot more work involved ! Need a wiring diagram an a component location chart an wiring harness routing diagram !
Most intermittent conditions are caused by faulty electrical connections or wiring. Inspect for the following items:
Wiring broken inside the insulation
Poor connection between the male and female terminal at a connector
Poor terminal to wire connection--Some conditions which fall under this description are poor crimps, poor solder joints, crimping over the wire insulation rather than the wire itself, and corrosion in the wire to terminal contact area, etc.
Pierced or damaged insulation can allow moisture to enter the wiring causing corrosion. The conductor can corrode inside the insulation, with little visible evidence. Look for swollen and stiff sections of wire in the suspect circuits.
Wiring which has been pinched, cut, or its insulation rubbed through may cause an intermittent open or short as the bare area touches other wiring or parts of the vehicle.
Wiring that comes in contact with hot or exhaust components
Refer to Inducing Intermittent Fault Conditions in order to duplicate the conditions required, in order to verify the customer concern.
Refer to Testing for Electrical Intermittents for test procedures to detect intermittent open, high resistance, short to ground, and short to voltage conditions.
Refer to Scan Tool Snapshot Procedure for advanced intermittent diagnosis and Vehicle Data Recorder operation.
You should take it to a ASE certified repair shop if not familiar with Automotive electronics !
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