Pinpoint Test I: The Start/Stop Switch Mode Indicator Is Always/Never Illuminated
Steering Column Switches
Pinpoint Test I: The Start/Stop Switch Mode Indicator Is Always/Never Illuminated
Normal Operation
The Body Control Module (BCM) uses a Field-Effect Transistor (FET) as circuit protection for the start/stop switch indicator and an electronic switch to turn the start/stop switch indicator on and off. The FET (Field-Effect Transistor) receives fused battery voltage from BCM (Body Control Module) fuse 18 (10A). When the start/stop switch is pressed a voltage and ground signal are sent to the BCM (Body Control Module). When the vehicle enters RUN or START mode, the BCM (Body Control Module) forward biases the FET (Field-Effect Transistor) which provides voltage to the amber LED in the start/stop switch, illuminating the word ENGINE.
- DTC B1240:11 (Start Button Mode Indicator: Circuit Short to Ground)- The BCM (Body Control Module) continuously monitors the start/stop switch indicator circuit, this DTC is set if the module detects a short to ground on the indicator circuit. When this DTC sets, the mode indicator circuit is disabled via the FET (Field-Effect Transistor). Once the condition that caused the DTC to set is repaired, the BCM (Body Control Module) must pass a self-test in order for the DTC to clear and the system to resume normal operation.
- DTC B1240:15 (Start Button Mode Indicator: Circuit Short to Battery or Open)- The BCM (Body Control Module) continuously monitors the start/stop switch indicator circuit, this DTC is set if the module detects a short to battery or an open on the indicator circuit. When this DTC sets, the mode indicator circuit is disabled via the FET (Field-Effect Transistor). Once the condition that caused the DTC to set is repaired, the BCM (Body Control Module) must pass a self-test in order for the DTC to clear and the system to resume normal operation.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Start/stop switch
- BCM (Body Control Module)
PINPOINT TEST I : THE START/STOP SWITCH MODE INDICATOR IS ALWAYS/NEVER ON
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
I1 REVIEW THE BCM (Body Control Module) DTCs
- Review the BCM (Body Control Module) DTCs retrieved and recorded during Inspection and Verification.
Is DTC B1240:11 present?
Yes
GO to I2.
No
If DTC B1240:15 is present, GO to I3.
For all other BCM (Body Control Module) DTCs, REFER to the Body Control Module (BCM) DTC Chart Steering Column Switches.
If no BCM (Body Control Module) DTCs are present, GO to I4.
I2 CHECK THE MODE INDICATOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: BCM (Body Control Module) C2280B.
- Disconnect: Start/Stop Switch C2195.
- Measure the resistance between start/stop switch C2195-2, circuit CPK36 (VT/BN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new start/stop switch. REFER to Start/Stop Switch Service and Repair. CARRY OUT a self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
No
REPAIR circuit CPK36 (VT/BN). CARRY OUT a self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
I3 CHECK THE MODE INDICATOR CIRCUIT FOR A SHORT TO VOLTAGE
NOTE: Disconnecting BCM (Body Control Module) C2280B with the ignition in RUN mode causes DTCs to set in some modules.
- Ignition ON.
- Disconnect: BCM (Body Control Module) C2280B.
- Disconnect: Start/Stop Switch C2195.
- Measure the voltage between start/stop switch C2195-2, circuit CPK36 (VT/BN), harness side and ground.
Is any voltage present?
Yes
REPAIR circuit CPK36 (VT/BN). CARRY OUT a self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
No
GO to I5.
I4 CHECK THE MODE INDICATOR CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: BCM (Body Control Module) C2280B.
- Disconnect: Start/Stop Switch C2195.
- Measure the resistance between start/stop switch C2195-2, circuit CPK36 (VT/BN), harness side and BCM (Body Control Module) C2280B-42, circuit CPK35 (VT/BN), harness side.
Is the resistance less than 5 ohms?
Yes
INSTALL a new start/stop switch. REFER to Start/Stop Switch Service and Repair. CARRY OUT a self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
No
REPAIR circuit CPK36 (VT/BN). CARRY OUT a self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
I5 CHECK FOR CORRECT BCM (Body Control Module) OPERATION
- Disconnect: All BCM (Body Control Module) Connectors.
- Check BCM (Body Control Module) connectors for:
- corrosion
- damaged pins
- pushed-out pins
- Connect: All BCM (Body Control Module) Connectors.
- Connect: Start/Stop Switch C2195.
- Make sure the connectors are seated correctly, then carry out a BCM (Body Control Module) self-test.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new BCM (Body Control Module). REPEAT the self-test.
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.