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/BCM for schematic and connector information. Diagrams By Number
Normal Operation
The ignition switch receives fused battery voltage from the Body Control Module (BCM) permanent voltage bus through fuse 28 (15A). In the ACC or ON position, voltage is sent to the BCM. In the START position, voltage is sent to both the BCM and PCM.
When the ignition switch is cycled to the OFF/LOCK position from any other position, the BCM begins a monitoring cycle. The monitoring cycle checks that the voltage supplied to the BCM from the ignition switch through the RUN/ACC, RUN/START and START circuits is delivered correctly for each ignition switch position.
- DTC U300A:01 (Ignition Switch: General Electric Failure) - the BCM continuously monitors the ignition switch position. This DTC sets if the voltage inputs to the BCM do not match the pre-defined configurations for each ignition switch position.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Ignition switch
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 CHECK THE IGNITION SWITCH
- Ignition OFF.
- 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. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
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A2 CHECK FOR VOLTAGE TO THE IGNITION SWITCH
- Measure the voltage between ignition switch C250-4, circuit SBP28 (GN/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A5.
No
VERIFY BCM fuse 28 (15A) is OK. If OK, GO to A3. If not OK, REFER to the Wiring Diagrams to identify the possible cause of the circuit short. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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A3 CHECK FOR VOLTAGE TO BCM
- Measure the voltage between BCM fuse 28 (15A), circuit SBP28 (GN/RD), and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A4
No
VERIFY fusible links A and B are OK. If OK, REPAIR circuit SDC04 (RD or GY). If not OK, REFER to the Wiring Diagrams to identify the possible cause of the circuit short. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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A4 CHECK FOR AN OPEN BETWEEN THE BCM AND IGNITION SWITCH
- Disconnect: BCM C2280A.
- Measure the resistance between BCM C2280A-6 and ignition switch C250-4, circuit SBP28 (GN/RD), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to A6.
No
REPAIR circuit SBP28 (GN/RD) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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A5 CHECK THE IGNITION SWITCH OUTPUT CIRCUITS FOR AN OPEN
- Disconnect: BCM C2280B.
- Measure the resistance between ignition switch C250, harness side and BCM C2280B, harness side as follows:
- Are the resistances less than 5 ohms?
Yes
GO to A6.
No
REPAIR the affected circuit(s). CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
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A6 CHECK FOR CORRECT BCM OPERATION
- Disconnect all BCM connectors.
- Check the connectors for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all BCM connectors and make sure they are seated correctly.
- Connect: Ignition Switch C250.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new BCM. REFER to Multifunction Electronic Modules Service and Repair. CLEAR the DTCs. REPEAT the self-test. 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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