Pinpoint Test L: The Turn Signal Lamps Are Inoperative
Turn Signal and Hazard Lamps
Pinpoint Tests
Pinpoint Test L: The Turn Signal Lamps Are Inoperative
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends reference signals to the multifunction switch through circuits CLS39 (VT/WH) (LH turn input) and CLS41 (GY/YE) (RH turn input). When the multifunction switch is placed in the LH or RH TURN positions, the voltage signal is routed to ground through circuit GD111 (BK/BU). When the SJB detects the multifunction switch in the LH or RH TURN position, the SJB provides on/off voltage to the appropriate turn lamps.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Multifunction switch
- SJB
PINPOINT TEST L: THE TURN SIGNAL LAMPS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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L1 CHECK FOR CORRECT HIGH BEAM OPERATION
- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position while observing the high beam headlamps.
- Do the high beams operate correctly?
Yes
For Taurus or Taurus X, GO to L2.
For Sable, VERIFY the SJB fuse 6 (20A) is OK. If OK, GO to L3. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short.
No
REFER to Headlamps.
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L2 CHECK THE STOPLAMP OPERATION
- Apply and release the brake pedal while observing the stoplamps.
- Do the stoplamps operate correctly?
Yes
GO to L3.
No
REFER to Stoplamps Testing and Inspection.
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L3 BYPASS THE MULTIFUNCTION SWITCH
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Disconnect: Multifunction Switch C202.
- For an inoperative LH turn signal, connect a fused jumper wire between the multifunction switch C202-2, circuit CLS39 (VT/WH), harness side and the multifunction switch C202-8, circuit GD111 (BK/BU), harness side.
- For an inoperative RH turn signal, connect a fused jumper wire between the multifunction switch C202-3, circuit CLS41 (GY/YE), harness side and the multifunction switch C202-8, circuit GD111 (BK/BU), harness side.
- Ignition ON.
- Do the turn signals in question flash on and off?
Yes
REMOVE the jumper wire. INSTALL a new multifunction switch. TEST the system for normal operation.
No
REMOVE the jumper wire. GO to L4.
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L4 CHECK TURN SIGNAL REQUEST INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: SJB C2280b.
- For the LH turn signal, measure the resistance between the multifunction switch C202-2, circuit CLS39 (VT/WH), harness side and the SJB C2280b-42, circuit CLS39 (VT/WH), harness side.
- For the RH turn signal, measure the resistance between the multifunction switch C202-3, circuit CLS41 (GY/YE), harness side and the SJB C2280b-29, circuit CLS41 (GY/YE), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to L5.
No
REPAIR circuit CLS39 (VT/WH) (LH turn signal) or circuit CLS41 (GY/YE) (RH turn signal) for an open. TEST the system for normal operation.
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L5 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new SJB. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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