Pinpoint Test C : One Rear Turn Signal Lamp Is Inoperative Or Always On

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

C1 DETERMINE IF ANY TURN LAMP IS ALWAYS ON
- Ignition ON.
- Activate the hazard lamp function.
- Observe the rear turn lamps.
Is any turn lamp continuously illuminated (not flashing)?

Yes GO to C2

No GO to C3

C2 CHECK THE REAR TURN LAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Deactivate the hazard lamp function.
- Disconnect: BCM C2280E .
- Ignition ON.
Does the turn lamp in question continue to illuminate?

Yes REPAIR the circuit in question.

No GO to C8

C3 CHECK FOR REAR TURN LAMP SUPPLY VOLTAGE

Ignition OFF.

Deactivate the hazard flasher lamp function.

Disconnect: LH Rear Lamp C412 or RH Rear Lamp C415 .

Ignition ON.

Activate the hazard flasher lamp function.

Measure:

LH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C412-4	Courtesy of FORD MOTOR COMPANY	Ground

RH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C415-4	Courtesy of FORD MOTOR COMPANY	Ground

Does the voltage alternate from 0 to greater than 11 volts?

Yes

GO to C5

GO to C4

C4 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE REAR TURN LAMP

Using a diagnostic scan tool, perform the BCM self-test.

Clear the Diagnostic Trouble Codes (DTCs) and repeat the self-test (required to enable the lamp output driver if DTC U1000:00 is present).

Measure:

LH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C412-4	Courtesy of FORD MOTOR COMPANY	Ground

RH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C415-4	Courtesy of FORD MOTOR COMPANY	Ground

Does the voltage alternate from 0 to greater than 11 volts?

Yes	INSTALL a new rear lamp assembly. REFER to: Rear Lamp Assembly .

GO to C6

C5 CHECK THE REAR TURN LAMP GROUND CIRCUIT FOR AN OPEN

Measure:

LH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C412-4	Courtesy of FORD MOTOR COMPANY	C412-1

RH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C415-4	Courtesy of FORD MOTOR COMPANY	C415-1

Does the voltage alternate from 0 to greater than 11 volts?

Yes	INSTALL a new rear lamp assembly. REFER to: Rear Lamp Assembly .

No	REPAIR the circuit.

C6 CHECK THE REAR TURN LAMP SUPPLY CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Deactivate the hazard flasher lamp function.

Disconnect: BCM C2280E .

Measure:

LH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C412-4	Courtesy of FORD MOTOR COMPANY	Ground

RH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C415-4	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to C7

REPAIR the circuit. After the repair:If no Diagnostic Trouble Codes (DTCs) are present, TEST the system for normal operation. If any BCM Diagnostic Trouble Codes (DTCs) other than DTC U3000:49 are present, CLEAR the Diagnostic Trouble Codes (DTCs), REPEAT the self-test (required to enable the lamp output driver) and cycle the ignition OFF and ON. TEST the system for normal operation. If DTC U3000:49 is present, BCM guided routine is not applicable for this vehicle and market. Replace the component that was faulted through service information diagnosis.

C7 CHECK THE REAR TURN LAMP SUPPLY CIRCUIT FOR AN OPEN

Measure:

LH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C412-4	Courtesy of FORD MOTOR COMPANY	C2280E-26

RH Rear Turn Lamp

Positive Lead	Measurement / Action	Negative Lead
C415-4	Courtesy of FORD MOTOR COMPANY	C2280E-52

Is the resistance less than 3 ohms?

Yes

GO to C8

No	REPAIR the circuit.

C8 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

Disconnect and inspect all BCM and all related in-line connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the BCM and all related in-line connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, BCM guided routine is not applicable for this vehicle and market. Replace the component that was faulted through service information diagnosis.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.