Ford Fiesta: Exterior Lighting / Autolamps. Diagnosis and Testing
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
DTC Chart: BCM
BCM
DTC Chart
DTC
|
Description
|
Action
|
B1A85:21
|
Ambient Light Sensor: Signal Amplitude < Minimum
|
GO to Pinpoint Test B
|
B1A85:22
|
Ambient Light Sensor: Signal Amplitude > Maximum
|
GO to Pinpoint Test B
|
Symptom Chart(s)
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Symptom Chart: Autolamps
Symptom Chart
Condition
|
Possible Sources
|
Actions
|
A module does not respond to the diagnostic scan tool
|
-
Fuse
-
Wiring, terminals or connectors
-
Module
|
REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing).
|
The autolamps are inoperative
|
Refer to the Pinpoint Test
|
GO to Pinpoint Test A
|
The autolamps are on continuously
|
Refer to the Pinpoint Test
|
GO to Pinpoint Test B
|
Pinpoint Tests
The Autolamps Are Inoperative
Refer to Wiring Diagrams Cell 71 for schematic and connector information.
Normal Operation and Fault Conditions
REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).
Possible Sources
-
Light sensor
-
Headlamp switch
-
BCM
PINPOINT TEST A: THE AUTOLAMPS ARE INOPERATIVE
A1 CHECK FOR VOLTAGE TO THE LIGHT SENSOR |
-
Disconnect: Light Sensor C2360 (EATC ).
-
Disconnect: Light Sensor C287 (EMTC ).
-
Place the headlamp switch in the autolamps on position.
Is the voltage approximately 5 volts?
Yes |
INSTALL a new light sensor.
|
|
A2 CHECK FOR CORRECT BCM (BODY CONTROL MODULE)
OPERATION |
-
Disconnect and inspect all BCM 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 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 Technical Service Bulletins (TSBs). If a
TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB
instructions. If no Technical Service Bulletins (TSBs) address this
concern, INSTALL a new BCM . REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
|
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.
|
|
The Autolamps Are On Continuously
Refer to Wiring Diagrams Cell 71 for schematic and connector information.
Normal Operation and Fault Conditions
REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).
DTC Fault Trigger Conditions
DTC
|
Description
|
Fault Trigger Conditions
|
B1A85:21
|
Ambient Light Sensor: Signal Amplitude < Minimum
|
A continuous memory DTC that sets when the BCM detects a short to ground from the light sensor input circuit.
|
B1A85:22
|
Ambient Light Sensor: Signal Amplitude > Maximum
|
A continuous memory DTC that sets when the BCM detects an open or short to voltage from the light sensor input circuit.
|
Possible Sources
-
Wiring, terminals or connectors
-
Light sensor
-
Headlamp switch
-
BCM
Visual Inspection and Diagnostic Pre-checks
-
Inspect the headlamp switch for damage.
-
Inspect the light sensor for damage.
PINPOINT TEST B: THE AUTOLAMPS ARE ON CONTINUOUSLY
B1 CHECK FOR BCM (BODY CONTROL MODULE)
DIAGNOSTIC TROUBLE CODE (DTCS) |
-
Using a diagnostic scan tool, perform the BCM self-test.
Is DTC B1A85:21 or B1A85:22 present?
Yes |
For DTC B1A85:21, GO to B3
For DTC B1A85:22, GO to B5
|
|
B2 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (NO DTC (DIAGNOSTIC TROUBLE CODE)
) |
-
Disconnect: Light Sensor C2360 (EATC ).
-
Disconnect: Light Sensor C287 (EMTC ).
-
Place the headlamp switch in the autolamps on position.
Is the voltage approximately 5 volts?
Yes |
INSTALL a new light sensor.
|
|
B3 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC (DIAGNOSTIC TROUBLE CODE)
B1A85:21) |
-
Disconnect: Light Sensor C2360 (EATC ).
-
Disconnect: Light Sensor C287 (EMTC ).
Is the voltage approximately 5 volts?
Yes |
INSTALL a new light sensor.
|
|
B4 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO GROUND |
Is the resistance greater than 10,000 ohms?
|
B5 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC (DIAGNOSTIC TROUBLE CODE)
B1A85:22) |
-
Disconnect: Light Sensor C2360 (EATC ).
-
Disconnect: Light Sensor C287 (EMTC ).
Is the voltage approximately 5 volts?
|
B6 CHECK THE LIGHT SENSOR |
Is the voltage approximately 5 volts?
Yes |
INSTALL a new light sensor.
|
|
B7 CHECK THE LIGHT SENSOR GROUND CIRCUIT FOR AN OPEN |
Is the resistance less than 3 ohms?
|
B8 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE |
Is any voltage present?
|
B9 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR AN OPEN |
Is the resistance less than 3 ohms?
|
B10 CHECK FOR CORRECT BCM (BODY CONTROL MODULE)
OPERATION |
-
Disconnect and inspect all BCM 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 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 Technical Service Bulletins (TSBs). If a
TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB
instructions. If no Technical Service Bulletins (TSBs) address this
concern, INSTALL a new BCM . REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
|
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.
|
|
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods (100-00 General Information, Description and Operation)...
Symptom Chart(s)
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.REFER to: Diagnostic Methods (100-00 General Information, Description and Operation)...
Other information:
Special Tool(s) /
General Equipment
Resistance Spotwelding Equipment
Air Body Saw
8 mm Drill Bit
MIG/MAG Welding Equipment
Spot Weld Drill Bit
Removal
WARNING:
Before beginning any service procedure in this
manual, refer to Safety Warnings in section 100-00 General Information...
Adjustment
Refer to: Jacking and Lifting - Overview (100-02 Jacking and Lifting, Description and Operation).
Remove the battery tray.
Refer to: Battery Tray - 1.6L EcoBoost (132kW/180PS) – Sigma (414-01 Battery, Mounting and Cables, Removal and Installation)...
Categories
Removal
NOTE:
Removal steps in this procedure may contain installation details.
Remove the brake shoes.
Refer to: Brake Shoes (206-02 Drum Brake, Removal and Installation).
Disconnect the brake tube fitting.
Torque:
159 lb.in (18 Nm)
Remove the bolt and wheel cylinder.
Torque:
106 lb.in (12 Nm)
Disconnect the brake shoe lever fitting and re
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