Interior Lighting System: Other Mercury Montego III

Possible Causes

1. An open in circuit 1205 (BK)
2. Smart junction box (SJB)

Scheme 24

1. A1 CHECK CIRCUIT 1205 (BK) FOR AN OPEN Key in OFF position. Disconnect: Overhead Console (w/o roof opening panel) C929 or (with roof opening panel) C930. Measure the resistance between overhead console C929-2 or C930-4, circuit 1205 (BK) and between and ground. Is the resistance less than 5 ohms? Yes : GO to A2. No : REPAIR circuit 1205 (BK) for an open. TEST the system for normal operation.
2. A2 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. An open in circuit 1404 (YE)
2. Smart junction box (SJB)
3. Dimmer control

Scheme 25

1. B1 CHECK CIRCUIT 1404 (YE) FOR AN OPEN Key in OFF position. Disconnect: Dimmer Control C2065. Disconnect: Smart Junction Box (SJB) C2280d. Measure the resistance between SJB C2280d-11, circuit 1404 (YE) and dimmer control C2065-5, circuit 1404 (YE). Is the resistance less than 5 ohms? Yes : CARRY out the dimmer control/interior lamp switch component test. If OK, GO to B2. No : REPAIR circuit 1404 (YE) for an open. TEST the system for normal operation.
2. B2 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. An open in circuits 53 (BK/LB) or 1205 (BK)
2. Lamp
3. Smart junction box (SJB)

Scheme 26

Scheme 27

Scheme 28

1. C1 CHECK CIRCUIT 1205 (BK) FOR AN OPEN Key in OFF position. Disconnect: Second Row Dome Lamp C961. Disconnect: Third Row Dome Lamp C963 (if equipped). Disconnect: Cargo Lamp C428 (if equipped). Disconnect: Overhead Console (w/o roof opening panel) C929 or (with roof opening panel) C930. Measure the resistance between ground and the inoperative lamp: overhead console C929-2 or C930-4, circuit 1205 (BK). cargo lamp C428-2, circuit 1205 (BK). second row dome lamp C961-2, circuit 1205 (BK). third row dome lamp C963-2, circuit 1205 (BK). Is the resistance less than 5 ohms? Yes : GO to C2. No : REPAIR circuit 1205 (BK) for an open. TEST the system for normal operation.
2. C2 CHECK CIRCUIT 53 (BK/LB) FOR VOLTAGE Open any door. Measure the voltage between ground and the inoperative lamp: overhead console C929-3 or C930-7, circuit 53 (BK/LB). cargo lamp C428-1, circuit 53 (BK/LB). second row dome lamp C961-1, circuit 53 (BK/LB). third row dome lamp C963-1, circuit 53 (BK/LB). Is the voltage greater than 10 volts? Yes : INSTALL a new lamp. TEST the system for normal operation. No : GO to C3.
3. C3 CHECK CIRCUIT 53 (BK/LB) FOR AN OPEN Disconnect: Smart Junction Box (SJB) C2280e. Measure the resistance between SJB C2280e-7, circuit 53 (BK/LB) and the inoperative lamp: overhead console C929-2 or C930-4, circuit 53 (BK/LB). cargo lamp C428-2, circuit 53 (BK/LB). second row dome lamp C961-2, circuit 53 (BK/LB). third row dome lamp C963-2, circuit 53 (BK/LB). Is the resistance less than 5 ohms? Yes : INSTALL a new SJB. TEST the system for normal operation. GO to C4. No : REPAIR the circuit for an open. TEST the system for normal operation.
4. C4 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. An open in circuits 2010 (YE/RD) or 1205 (BK)
2. Lamp
3. Smart junction box (SJB)

Scheme 29

Scheme 30

1. D1 CHECK CIRCUIT 2010 (YE/RD) FOR VOLTAGE Key in OFF position. Disconnect: Memory Mirror (LH) C516 or (RH) C625. Disconnect: Non-Memory Mirror (LH) C522 or (RH) C622. Open any door. Measure the voltage between ground and: CONNECTOR PIN REFERENCE Description Connector Circuit With Memory Mirrors LH mirror C516-8 2010 (YE/RD) RH mirror C625-8 2010 (YE/RD) Without Memory Mirrors LH mirror C522-4 2010 (YE/RD) RH mirror C622-4 2010 (YE/RD) Is the voltage greater than 10 volts? Yes : INSTALL a new mirror. TEST the system for normal operation. No : GO to D2.
2. D2 CHECK CIRCUIT 2010 (YE/RD) FOR AN OPEN Key in OFF position. Disconnect: Smart Junction Box (SJB) C2280e. Measure the resistance between SJB C2280e-12, circuit 2010 (YE/RD) and: CONNECTOR PIN REFERENCE Description Connector Circuit With Memory Mirrors LH mirror C516-8 2010 (YE/RD) RH mirror C625-8 2010 (YE/RD) Without Memory Mirrors LH mirror C522-4 2010 (YE/RD) RH mirror C622-4 2010 (YE/RD) Is the resistance less than 5 ohms? Yes : GO to D3. No : REPAIR circuit 2010 (YE/RD) for an open. TEST the system for normal operation.
3. D3 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. LH front door ajar switch circuit 1312 (LG/BK)
2. RH front door ajar switch circuit 1314 (YE/LG)
3. LH rear door ajar switch circuit 1742 (VT/LG)
4. RH rear door ajar switch circuit 1754 (RD)
5. Liftgate ajar switch circuit 700 (WH/VT)
6. Decklid ajar switch circuit 700 (WH/VT)

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

1. E1 CHECK THE DOOR, LIFTGATE AND DECKLID AJAR SJB PIDS Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Door, Liftgate and Decklid Ajar SJB PIDS. Close all doors and the liftgate or decklid. Does any door, liftgate or decklid ajar PID read open? Yes : GO to E3 . No : GO to E2.
2. E2 CHECK CIRCUIT 53 (BK/LB) FOR A SHORT TO VOLTAGE Key in OFF position. Disconnect: Smart Junction Box (SJB) C2280e. Key in ON position. Measure the voltage between the SJB C2280e-7, circuit 53 (BK/LB) and ground. Is voltage present? Yes : GO to E6 . No : REPAIR circuit 53 (BK/LB) for a short to voltage. TEST the system for normal operation.
3. E3 CHECK CIRCUIT 1205 (BK) FOR AN OPEN Key in OFF position. Disconnect: Inoperative Front Ajar Switch (LH) C526 or (RH) C602, Rear Ajar Switch (LH) C715 or (RH) C820, Liftgate Ajar Switch C479 or Decklid Ajar Switch C4302. Measure the resistance between ground and: (front door ajar switch indicated open) front door ajar switch (LH) C526-1 or (RH) C602-1, circuit 1205 (BK). (rear door ajar switch indicated open) rear door ajar switch (LH) C715-1 or (RH) C820-1, circuit 1205 (BK). (liftgate ajar switch indicated open) liftgate ajar switch C479-B, circuit 1205 (BK). (decklid ajar switch indicated open) decklid ajar switch C4302-3, circuit 1205 (BK). Is the resistance less than 5 ohms? Yes : GO to E4. No : REPAIR circuit 1205 (BK) for an open. TEST the system for normal operation.
4. E4 CHECK THE AJAR SWITCH NOTE: Door ajar switch indicated open. Place a fused jumper between: LH front door ajar switch C526-1, circuit 1205 (BK) and LH front door ajar switch C526-2, circuit 1312 (LG/BK). RH front door ajar switch C602-1, circuit 1205 (BK) and RH front door ajar switch C602-2, circuit 1314 (YE/LG). LH rear door ajar switch C715-1, circuit 1205 (BK) and LH rear door ajar switch C715-2, circuit 1742 (VT/LG). RH rear door ajar switch C820-1, circuit 1205 (BK) and RH rear door ajar switch C820-2, circuit 1754 (RD). NOTE: Liftgate ajar switch indicated open. Place a fused jumper between liftgate ajar switch C479-B, circuit 1205 (BK) and liftgate ajar switch C479-C, circuit 700 (WH/VT). NOTE: Decklid ajar switch indicated open. Place a fused jumper between decklid ajar switch C4302-3, circuit 1205 (BK) and decklid ajar switch C4302-1, circuit 700 (WH/VT). Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Door, Liftgate and Decklid Ajar SJB PIDS. Does the door, liftgate or decklid ajar PID still read open? Yes : GO to E5. No : INSTALL a new ajar switch. TEST the system for normal operation.
5. E5 CHECK THE DOOR AJAR SIGNAL CIRCUIT FOR OPEN Key in OFF position. Disconnect: Smart Junction Box (SJB) C2280c. Measure the resistance between: (LH front door ajar switch indicated open) SJB C2280c-20, circuit 1312 (LG/BK) and LH front door ajar switch C526-2, circuit 1312 (LG/BK). (RH front door ajar switch indicated open) SJB C2280c-22, circuit 1314 (YE/LG) and RH front door ajar switch C602-2, circuit 1314 (YE/LG). (LH rear door ajar switch indicated open) SJB C2280c-7, circuit 1742 (VT/LG) and LH rear door ajar switch C715-2, circuit 1742 (VT/LG). (RH rear door ajar switch indicated open) SJB C2280c-6, circuit 1754 (RD) and RH rear door ajar switch C820-2, circuit 1754 (RD). (liftgate ajar switch indicated open) SJB C2280c-5, circuit 700 (WH/VT) and liftgate ajar switch C479-C, circuit 700 (WH/VT) (decklid ajar switch indicated open) SJB C2280c-5, circuit 700 (WH/VT) and decklid ajar switch C4302-1, circuit 700 (WH/VT) Is the resistance less than 5 ohms? Yes : GO to E6. No : REPAIR the circuit for an open. TEST the system for normal operation.
6. E6 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. A short to ground in circuits 1312 (LG/BK), 1314 (YE/LG), 1742 (VT/LG), 1754 (RD) or 700 (WH/VT)
2. Ajar switch(es)
3. SJB

Scheme 37

1. F1 CHECK THE DOOR, LIFTGATE AND DECKLID AJAR SJB PIDS Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Door, Liftgate and Decklid Ajar SJB PIDS. Open the inoperative door, liftgate or decklid. Does the door, liftgate or decklid ajar PID read open? Yes : GO to F4 . No : GO to F2.
2. F2 CHECK THE DOOR, LIFTGATE OR DECKLID AJAR SWITCH Key in OFF position. Disconnect: Inoperative Front Ajar Switch (LH) C526 or (RH) C602, Rear Ajar Switch (LH) C715 or (RH) C820, Liftgate Ajar Switch C479 or Decklid Ajar Switch C4302. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Door, Liftgate and Decklid Ajar SJB PIDS. Observe the inoperative door, liftgate or decklid ajar PID. Does the door, liftgate or decklid ajar PID read open? Yes : INSTALL a new ajar switch. TEST the system for normal operation. No : GO to F3.
3. F3 CHECK THE AJAR SIGNAL CIRCUIT FOR A SHORT TO GROUND Key in OFF position. Disconnect: SJB C2280c. Measure the resistance between ground and the: (LH front door ajar switch indicated closed) LH front door ajar switch C526-2, circuit 1312 (LG/BK). (RH front door ajar switch indicated closed) RH front door ajar switch C602-2, circuit 1314 (YE/LG). (LH rear door ajar switch indicated closed) LH rear door ajar switch C715-2, circuit 1742 (VT/LG). (RH rear door ajar switch indicated closed) RH rear door ajar switch C820-2, circuit 1754 (RD). (decklid ajar switch indicated closed) decklid ajar switch C4302-1, circuit 700 (WH/VT). (liftgate ajar switch indicated closed) liftgate ajar switch C479-C, circuit 700 (WH/VT). Is the resistance greater than 10,000 ohms? Yes : GO to F4. No : REPAIR the circuit for a short to ground. TEST the system for normal operation.
4. F4 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. An open in circuit 705 (LG/OG)
2. SJB

Scheme 38

1. G1 CHECK CIRCUIT 705 (LG/OG) FOR AN OPEN Key in OFF position. Disconnect: Overhead Console (w/o roof opening panel) C929 or (with roof opening panel) C930. Measure the resistance between SJB C2280e-16, circuit 705 (LG/OG) and: overhead console (with roof opening panel) C930-3, circuit 705 (LG/OG). overhead console (without roof opening panel) C929-1, circuit 705 (LG/OG). Are the resistances less than 5 ohms? Yes : GO to G2. No : REPAIR circuit 705 (LG/OG) for an open. TEST the system for normal operation.
2. G2 CHECK SJB PINS AND CONNECTORS Disconnect all SJB module connectors. Check for: corrosion pushed-out pins Connect all SJB module 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. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(ref-233027) . TEST the system for normal operation. No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.

1. An open in circuit 705 (LG/OG)
2. Lamp

Scheme 39

1. H1 CHECK DEMAND LAMP POWER CIRCUIT FOR VOLTAGE Key in OFF position. Disconnect: Inoperative Lamp. Measure the resistance between ground and the inoperative demand lamp: overhead console (with roof opening panel) C930-3, circuit 705 (LG/OG). overhead console (without roof opening panel) C929-1, circuit 705 (LG/OG). second row dome lamp C961-3, circuit 705 (LG/OG). third row dome lamp C963-3, circuit 705 (LG/OG). LH visor C907-1, circuit 705 (LG/OG). RH visor C906-1, circuit 705 (LG/OG). Is the voltage greater than 10 volts? Yes : INSTALL a new lamp. TEST the system for normal operation. No : REPAIR circuit 705 (LG/OG) for an open. TEST the system for normal operation.

1. An open in circuit 53 (BK/LB)
2. SJB