Pinpoint Test D : No Power In On - Push Button Ignition Switch: Notes
Refer to Power Distribution for schematic and connector information.
Refer to Starting System for schematic and connector information.
Normal Operation and Fault Conditions
To place the vehicle in ON mode, locate the passive key inside the vehicle and press the ignition switch once, for at least one second, without applying the brake pedal. When in ON mode, the BCM then activates the ignition and accessory relays, which distribute fused voltage to various components. The BCM uses a Field-Effect Transistor (FET) to control the relays. The ignition relay receives voltage from BJB fuse 23 (5A). The accessory relay receives voltage from high current BJB fuse 6 (70A).
To start the engine, locate the passive key inside the vehicle and press the ignition switch while applying the brake pedal.
The ignition switch provides a voltage input to the BCM, RFA module and PCM. The 3 modules exchange information over the HS-CAN to determine if starting the engine or turning the ignition ON is authorized. When the BCM determines that an ignition ON message is received, the BCM supplies power to the BCM fuses and relays. If the PATS authorizes the starting of the engine, the PCM supplies power and ground to the starter relay.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B108A:24 | Start Button: Signal Stuck High | Sets continuous when the BCM detects a short to voltage (a button press) from both push button ignition switch input circuits for more than 2 minutes. A stuck button can cause this code to set. |
| B108B:23 | Start Button Circuit "A": Signal Stuck Low | Sets continuous when the BCM detects a short to voltage (a button press) from the SW2 circuit but no voltage from the SW1 circuit. |
| B108B:24 | Start Button Circuit "A": Signal Stuck High | Sets continuous when the BCM detects a short to voltage (a button press) from the SW1 circuit for more than 60 seconds. |
| B108B:2F | Start Button Circuit "A": Signal Erratic | Sets during the on-demand self-test when the BCM detects a short to voltage (a button press) from the SW1 circuit. |
| B108C:23 | Start Button Circuit "B": Signal Stuck Low | Sets continuous when the BCM detects a short to voltage (a button press) from the SW1 circuit but no voltage from the SW2 circuit. |
| B108C:24 | Start Button Circuit "B": Signal Stuck High | Sets continuous when the BCM detects a short to voltage (a button press) from the SW2 circuit for more than 60 seconds. |
| B108C:2F | Start Button Circuit "B": Signal Erratic | Sets during the on-demand self-test when the BCM detects a short to voltage (a button press) from the SW2 circuit. |
| B10E7:12 | Ignition On Relay: Circuit Short to Battery | Sets when the BCM detects a short to voltage from the ignition relay output circuit when it has not activated the ignition relay. |
| B10E7:14 | Ignition On Relay: Circuit Short to Ground or Open | Sets when the BCM detects no voltage from the ignition relay output circuit when it has activated the ignition relay. |
| B10FF:12 | Ignition Control: Circuit Short To Battery | Sets when the BCM detects a short to voltage from the ignition relay control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the ignition must be switched off and then back on for the system to resume normal operation. |
| B10FF:14 | Ignition Control: Circuit Short To Ground or Open | Sets when the BCM detects no voltage from the ignition relay control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the ignition must be switched off and then back on for the system to resume normal operation. |
| B112A:12 | Ignition On Relay B: Circuit Short to Battery | The BCM continuously monitors the control side of the accessory relay. This DTC sets if the BCM detects a short to voltage on the accessory relay control circuit. When this DTC sets, the control side of the accessory relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
Possible Causes
- PATS concern
- RKE system concern
- Fuse
- Wiring, terminals or connectors
- Ignition relay
- Accessory relay
- RJB accessory relay
- Push button ignition switch
- BCM
- RFA module
- PCM
Visual Inspection and Diagnostic Pre-checks
- Inspect the high current BJB fuses 3 (100A) and 6 (70A).
- Inspect the BJB fuse 23 (5A).
- Inspect BCM fuse 78 (5A).