DESCRIPTION & OPERATION
| WARNING | Vehicle is equipped with air bag supplemental restraint system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article. |
Body control system controls the following systems: key unlock warning system and buzzer, headlights, taillights, interior lights, driver's seat belt warning indicator, open door warning indicator, power windows, power door locks and keyless entry system. Body Electronic Control Unit (ECU) is used for controlling these systems. Body ECU is incorporated into the passenger's side junction block. Body ECU is referred to as the passenger's side Junction Block (J/B) ECU.
TEST NO. 27: POWER DOOR LOCKS MAY NOT BE LOCKED OR UNLOCKED WHEN USING THE KEY, OR TWO-OPERATION UNLOCK FUNCTION DOES NOT OPERATE
Note. Two-operation unlock function unlocks all side doors and back (rear liftgate) door. When using the key and turning driver's side front door lock once, only driver's side front door will unlock. Turning driver's side front door lock twice in succession will unlock remaining side doors and the back (rear liftgate) door.
- Check door unlock detection switch on driver's side front door and passenger's side front door. See «DOOR UNLOCK DETECTION SWITCH»(ref-131965-S36272228222002010200000) under COMPONENT TESTS. If door unlock detection switches are okay, go to next step. If any door unlock detection switch is defective, replace door unlock detection switch and recheck power door lock or two-operation unlock function operation.
- Check wiring harness and electrical connectors between door unlock detection switch on driver's side front door and passenger's side front door and passenger's side Junction Block (J/B) Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Passenger's side J/B ECU is located at passenger's side of instrument panel. (Схема №2) If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck power door lock or two-operation unlock function operation.
- Check passenger's side J/B ECU for proper voltage and input signals. See «PASSENGER'S SIDE JUNCTION BLOCK ELECTRONIC CONTROL UNIT»(ref-131965-S18185280062002010200000) under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage and input signals do not exist, repair as necessary and recheck power door lock or two-operation unlock function operation.
- Replace passenger's side J/B ECU with a known-good passenger's side J/B ECU and recheck power door lock or two-operation unlock function operation. If power door lock or two-operation unlock function operates properly, original passenger's side J/B ECU was defective. If power door lock or two-operation unlock function still do not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU and door unlock detection switch for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Repair wiring harness or electrical connector as necessary.