Pinpoint Test A: No Power In All Ignition Switch Positions
Steering Column Switches
Pinpoint Tests
Pinpoint Test A: No Power in All Ignition Switch Positions
Refer to Wiring Diagram Set 13, Power Distribution/SJB for schematic and connector information. Diagrams By Number
Normal Operation
The Battery Junction Box (BJB) receives battery voltage along circuit SDC02 (RD) and distributes this voltage to various fuses. The ignition switch receives fused battery voltage from Smart Junction Box (SJB) fuse 27 (20A) along circuit SBP27 (BU/RD). The ignition switch distributes power from circuit SBP27 (BU/RD) to one of 3 circuits depending on the ignition switch position. The ignition switch positions are:
- OFF
- ACC - Power on circuit CDC33 (VT/GN) to the SJB
- RUN - Power on circuit CDC01 (GN/VT) to the SJB and BJB
- START - Power on circuit CDC35 (BU/WH) to the SJB, BJB and PCM
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Ignition switch
- BJB
- SJB
PINPOINT TEST A: NO POWER IN ALL IGNITION SWITCH POSITIONS
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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A1 ISOLATE THE IGNITION SWITCH
- Disconnect: Ignition Switch C250.
- Carry out the ignition switch component test.
- Is the ignition switch OK?
Yes
GO to A2.
No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. TEST the system for normal operation.
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A2 CHECK FOR POWER TO THE IGNITION SWITCH
- Measure the voltage between ignition switch C250-4, circuit SBB27 (BU/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
No
GO to A3.
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A3 CHECK THE IGNITION SWITCH INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB Fuse 27 (20A).
- Measure the resistance between ignition switch C250-4, circuit SBB27 (BU/RD), harness side and SJB fuse 27 (20A), output side.
- Is the resistance less than 5 ohms?
Yes
GO to A4.
No
VERIFY SJB fuse 27 (20A) is OK.
If OK, REPAIR circuit SBB27 (BU/RD). TEST the system for normal operation.
If not OK, GO to A7.
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A4 CHECK THE IGNITION SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between ignition switch C250-4, circuit SBB27 (BU/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to A5.
No
REPAIR circuit SBB27 (BU/RD). TEST the system for normal operation.
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A5 CHECK FOR POWER TO SJB FUSE 27 (20A)
- Measure the voltage between SJB fuse 27 (20A), input side and ground.
- Is the voltage greater than 10 volts?
Yes
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
No
GO to A6.
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A6 CHECK FOR POWER TO THE SJB FUSE 18 (20A)
- Disconnect: SJB Fuse 18 (20A).
- Measure the voltage between SJB fuse 18 (20A), input side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A10.
No
GO to A7.
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A7 CHECK FOR POWER TO THE SJB
- Disconnect: SJB C2280G.
- Measure the voltage between SJB C2280G-1, circuit SBB01 (RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new SJB fuse 27 (20A).
No
GO to A8.
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A8 CHECK THE SJB B+ INPUT CIRCUIT FOR AN OPEN
- Disconnect: BJB Fuse 1 (80A).
- Disconnect: BJB Fuse 2 (80A).
- Measure the resistance between BJB fuse 1 (80A), output side and SJB
C2280G-1, circuit SBB01 (RD), harness side.
- Measure the resistance between BJB, fuse 2 (80A), output side and SJB
C2280G-1, circuit SBB01 (RD), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to A9.
No
REPAIR circuit SBB01 (RD). TEST the system for normal operation.
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A9 CHECK FOR POWER TO THE BJB
- Measure the voltage at BJB fuse 1 (80A) input side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new SJB fuse 27 (20A).
No
VERIFY BJB fuses 1 (80A) and 2 (80A) are OK. If OK, REPAIR circuit SDC02 (RD).
If a fuse is not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
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A10 CHECK FOR CORRECT SJB OPERATION
- Disconnect all SJB connections.
- Check the SJB connections for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect the SJB connections and make sure they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new SJB. REFER to Body Control Systems. CLEAR the DTCs. 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. TEST the system for normal operation.
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