Ford Fiesta Quiz
Lighting

Back-Up Lamps. Diagnosis and Testing

In this manual: Lighting
Service Information — 27Suspension — 48Transmission — 9Brake System — 52Steering — 21Engine — 140Manual Transmission, Clutch, Transfer Case and Power Transfer Unit — 48Exhaust System — 6Fuel System — 21Climate Control System — 58Instrumentation and Warning Systems — 26Battery and Charging System — 20Infotainment Systems — 41Lighting — 29Power Distribution — 11Electronic Function Group — 30Body and Paint — 275Frame and Mounting — 3
~12min read

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

DTC Chart: BCM

DTC Chart


BCM Description Action
C1137:24 Reverse Gear Switch: Stuck High GO to Pinpoint Test C

Symptom Chart

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Symptom Chart: Back-Up Lamps

Symptom Chart


Condition Possible Sources Action
Module Does Not Respond to Diagnostic Scan Tool
  • Fuse
  • Wiring, Terminals or Connectors
  • Module
REFER TO: Communication Network (418-00 Communication Network, Diagnosis and Testing).
All Back-Up Lamps Inoperative Refer to Pinpoint Test GO to Pinpoint Test A
Individual back-up lamp inoperative Refer to Pinpoint Test GO to Pinpoint Test B
Back-Up Lamps Continuously On Refer to Pinpoint Test GO to Pinpoint Test C

Pinpoint Tests

All Back-Up Lamps Inoperative


For circuit and connector information, refer to Wiring Diagrams Cell 93.

Normal Operation and Fault Symptoms


REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).

Possible Sources

  • Fuse
  • Wiring, Terminals or Connectors
  • Back-Up Lamp Switch (manual transmission)
  • Back-Up Lamp Relay (automatic transmission)
  • TCM (automatic transmission)

Visual Inspection and Preliminary Diagnosis

  • Inspect fuse 6 CJB (10A).

DIAGNOSTIC TEST A: ALL BACK-UP LAMPS INOPERATIVE
A1 DETERMINE THE TRANSMISSION TYPE
  • Check the vehicle for a manual transmission.

Is the vehicle equipped with a manual transmission?
Yes ENSURE that fuse 6 CJB (10A) is serviceable. If serviceable, GO to A2. If not serviceable, REFER to the Wiring Diagrams manual to determine the possible cause of the short circuit.
No ENSURE that fuse 6 CJB (10A) is serviceable. If serviceable, GO to A4. If not serviceable, REFER to the Wiring Diagrams manual to determine the possible cause of the short circuit.
A2 CHECK THE VOLTAGE AT THE BACK-UP LAMP SWITCH
  • Ignition OFF.
  • Disconnect: Back-Up Lamp Switch C1131.
  • The ignition is on.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C1131-1 Ground

Is the voltage greater than 11 volts?
Yes GO to A3
No REPAIR the circuit.
A3 BACK-UP LAMP SWITCH LOCKED
  • Connect a fused jumper wire:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C1131-1 C1131-2

Are the back-up lamps on?
Yes REMOVE the fusible link. INSTALL a new back-up lamp switch.
REFER TO: Back-Up Lamp Switch (417-01 Exterior Lighting, Removal and Installation).
No For 4-door vehicles, REMOVE the fusible link. GO to A9.
For 5-door vehicles, REMOVE the fusible link. REPAIR the back-up lamp power circuit.
A4 CHECK THE BACK-UP LAMP RELAY
  • Disconnect: Back-Up Lamp Relay.
  • The ignition is on.
  • Replace with a known-good relay and recheck the back-up lamp operation.

Do the back-up lamps operate correctly?
Yes REMOVE the known-good relay. INSTALL a new back-up lamp relay.
No REMOVE the known-good relay. GO to A5.
A5 CHECK THE VOLTAGE AT THE BACK-UP LAMP RELAY
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    Back-Up Lamp Relay, Terminal 1 Ground

    Click to display connectors
    Positive lead Measurement/Action Negative lead
    Back-Up Lamp Relay, Terminal 3 Ground

Is the voltage greater than 10 volts?
Yes GO to A6
No REPAIR the faulty circuit.
A6 BACK-UP LAMP RELAY LOCKED
  • Connect a fused jumper wire:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    Back-Up Lamp Relay, Terminal 3 Back-Up Lamp Relay, Terminal 5

Are the back-up lamps on?
Yes REMOVE the fusible link. GO to A7.
No For 4-door vehicles, REMOVE the fusible link. GO to A9.
For 5-door vehicles, REMOVE the fusible link. REPAIR the back-up lamp power circuit.
A7 CHECK THE BACK-UP LAMP RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: TCM C1750A.
  • The ignition is on.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    Back-Up Lamp Relay, Terminal 2 Ground

Is there voltage present?
Yes REPAIR the circuit.
No GO to A8
A8 CHECK THE BACK-UP LAMP RELAY CONTROL CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    Back-Up Lamp Relay, Terminal 2 C1750A-40

Is the resistance less than 3 ohms?
Yes GO to A10
No REPAIR the circuit.
A9 CHECK THE BACK-UP LAMP GROUND CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Disconnect: Left Back-Up Lamp C498.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C498-1 C498-4

Is the resistance less than 3 ohms?
Yes REPAIR the back-up lamp power circuit.
No REPAIR the circuit.
A10 CHECK THE 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
    • backed-out pins - install new pins as necessary
  • Reconnect the BCM connectors. Make sure they are fully seated and locked.
  • 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, STOP this test and FOLLOW the TSB instructions. If no TSBs apply to this concern, INSTALL a new BCM.
REFER TO: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.

One Back-Up Lamp Inoperative


For circuit and connector information, refer to Wiring Diagrams Cell 93.

Normal Operation and Fault Symptoms


REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).

Possible Sources

  • Lamp
  • Wiring, Terminals or Connectors

DIAGNOSTIC TEST B: ONE BACK-UP LAMP INOPERATIVE
B1 BACK-UP LAMP VOLTAGE CHECK
  • Ignition OFF.
  • Apply the parking brake.
  • Disconnect: 4-door inoperative Left Back-Up Lamp C498 or Right Back-Up Lamp C499.
  • Disconnect: 5-door inoperative Left Back-Up Lamp C414 or Right Back-Up Lamp C417.
  • The ignition is on.
  • Place the gearshift lever in the REVERSE position.
  • Action:
    Click to display the connectors

    4-door LH back-up lamp


    Positive lead Measurement/Action Negative lead
    C498-1 Ground

    Click to display the connectors

    4-door RH back-up lamp


    Positive lead Measurement/Action Negative lead
    C499-1 Ground

    Click to display the connectors

    5-door LH tail lamp


    Positive lead Measurement/Action Negative lead
    C414-3 Ground

    Click to display the connectors

    5-door RH tail lamp


    Positive lead Measurement/Action Negative lead
    C417-3 Ground

Is the voltage greater than 11 volts?
Yes GO to B2
No REPAIR the back-up lamp power circuit.
B2 CHECK THE BACK-UP LAMP GROUND CIRCUIT FOR AN OPEN
  • Action:
    Click to display the connectors

    4-door LH back-up lamp


    Positive lead Measurement/Action Negative lead
    C498-1 C498-4

    Click to display the connectors

    4-door RH back-up lamp


    Positive lead Measurement/Action Negative lead
    C499-1 C499-4

    Click to display the connectors

    5-door LH tail lamp


    Positive lead Measurement/Action Negative lead
    C414-3 C414-6

    Click to display the connectors

    5-door RH tail lamp


    Positive lead Measurement/Action Negative lead
    C417-3 C417-6

Is the voltage greater than 11 volts?
Yes On 4-door vehicles, INSTALL a new bulb.
For 5-door vehicles, ENSURE the bulb is serviceable. If serviceable, REPAIR or INSTALL a new rear lamp harness connector. If not serviceable, INSTALL a new bulb.
No REPAIR the circuit.

Back-Up Lamps Continuously On


For circuit and connector information, refer to Wiring Diagrams Cell 93.

Normal Operation and Fault Symptoms


REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).


DTC Fault Trigger Conditions


Trouble Code Description Fault Trigger Conditions
C1137:24 Reverse Gear Switch: Stuck High

Continuous on-demand DTC that sets when the BCM detects one of the following conditions:

  • Back-up lamp switch input voltage detected (transmission selector in REVERSE) for more than 1 second when vehicle speed exceeds 60 km/h.
  • Back-up lamp switch input circuit detects a short to ground during BCM self-test.

Possible Sources

  • Wiring, Terminals or Connectors
  • Gear Range Input
  • GPSM
  • TCM
  • Automatic Dimming Interior Rearview Mirror
  • BCM

DIAGNOSTIC TEST C: BACK-UP LAMPS CONTINUOUSLY ON
C1 DETERMINE THE TRANSMISSION TYPE
  • Check the vehicle for a manual transmission.

Is the vehicle equipped with a manual transmission?
Yes GO to C2
No GO to C3
C2 CHECK THE BACK-UP LAMP SWITCH
  • Ignition OFF.
  • Disconnect: Back-Up Lamp Switch C1131.
  • The ignition is on.

Do the back-up lamps remain on?
Yes If equipped with SYNC®, GO to C4.
If the SYNC® system is not equipped, GO to C5.
No INSTALL a new back-up lamp switch.
REFER TO: Back-Up Lamp Switch (417-01 Exterior Lighting, Removal and Installation).
C3 CHECK THE BACK-UP LAMP RELAY OUTPUT
  • Ignition OFF.
  • Disconnect: Back-Up Lamp Relay.
  • The ignition is on.

Do the back-up lamps remain on?
Yes If equipped with SYNC®, GO to C4.
If the SYNC® system is not equipped, GO to C5.
No GO TO C7
C4 CHECK THE GPSM (GLOBAL POSITIONING SYSTEM MODULE) FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: GPSM C9050.
  • The ignition is on.

Do the back-up lamps remain on?
Yes GO to C5
No GO TO C10
C5 CHECK THE BCM (BODY CONTROL MODULE) FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: BCM C2280D.
  • The ignition is on.

Do the back-up lamps remain on?
Yes If equipped with an automatic-dimming interior rearview mirror, GO TO C6.
If not equipped with an automatic-dimming interior rearview mirror, REPAIR the backup lamp feed circuit for a short to voltage.
No GO TO C11
C6 CHECK THE AUTOMATIC-DIMMING INTERIOR REARVIEW MIRROR FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: Automatic-dimming interior rearview mirror C911 (without rain sensor).
  • Disconnect: Automatic-dimming interior rearview mirror C9012 (with rain sensor).
  • The ignition is on.

Do the back-up lamps remain on?
Yes REPAIR the circuit.
No INSTALL a new automatic-dimming interior rearview mirror.
REFER TO: Interior Rearview Mirror (501-09 Mirrors, Removal and Installation).
C7 CHECK THE BACKUP LAMP RELAY
  • Ignition OFF.
  • Disconnect: Back-Up Lamp Relay.
  • The ignition is on.
  • Replace the relay with a known good relay.

Do the back-up lamps remain on?
Yes REMOVE the known good relay. GO TO C8.
No REMOVE the known-good relay. INSTALL a new back-up lamp relay.
C8 CHECK THE BACKUP LAMP RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Connect: Backup lamp relay.
  • Disconnect: TCM C1750A.
  • The ignition is on.

Do the back-up lamps remain on?
Yes REPAIR the circuit.
No GO TO C9
C9 CHECK THE TCM (TRANSMISSION CONTROL MODULE) GEAR STATE INPUT PID (PARAMETER IDENTIFICATION)
  • Ignition OFF.
  • Connect: TCM C1750A.
  • The ignition is on.
  • Using the diagnostic scan tool, view the TCM parameter identification (PID) values.
  • Monitor the TCM GEAR_ENGAGED PID while moving the gear selector lever through all of its positions.

Does the PID agree with the selected gear?
Yes GO TO C12
No
REFER TO: Automatic Transmission (307-01 Automatic Transmission - 6-Speed PowerShift Transmission - DPS6/6DCT250, Diagnosis and Testing).
for input gear diagnosis.
C10 CHECK THE GPSM (GLOBAL POSITIONING SYSTEM MODULE) FOR CORRECT OPERATION
  • Disconnect and inspect the GPSM connector.
  • Repair:
    • corrosion (install new connector or terminals - clean module pins)
    • damaged or bent pins - install new terminals/pins
    • backed-out pins - install new pins as necessary
  • Reconnect the GPSM connector. Make sure it is properly installed and latched.
  • Operate the system and determine if the concern is still present.

Is the concern still present?
Yes CHECK in OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this condition, STOP this test and FOLLOW the TSB instructions. If no TSB applies to this concern, INSTALL a new GPSM. For vehicles not equipped with a touchscreen,
REFER TO: Global Positioning System Module (GPSM) (415-00A Information and Entertainment System - General Information - Vehicles With: AM/FM/CD/SYNC, Removal and Installation).
For vehicles equipped with a touchscreen,
No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.
C11 CHECK THE BCM (BODY CONTROL MODULE) FOR NORMAL 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
    • backed-out pins - install new pins as necessary
  • Reconnect the BCM connectors. Make sure they are fully seated and locked.
  • 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, STOP this test and FOLLOW the TSB instructions. If no TSBs apply to this concern, INSTALL a new BCM.
REFER TO: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.
C12 CHECK THE TCM (TRANSMISSION CONTROL MODULE) FOR CORRECT OPERATION
  • Disconnect and inspect all TCM connectors.
  • Repair:
    • corrosion (install new connector or terminals - clean module pins)
    • damaged or bent pins - install new terminals/pins
    • backed-out pins - install new pins as necessary
  • Reconnect the TCM connectors. Make sure they are installed and locked 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, STOP this test and FOLLOW the TSB instructions. If no TSB applies to this concern, INSTALL a new TCM.
REFER TO: Transmission Control Module (TCM) (307-01 Automatic Transmission - 6-Speed PowerShift Transmission - DPS6/6DCT250, Removal and Installation).
No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.

Test yourself

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