Pinpoint Test C : No Power In On - Conventional Ignition Switch: Notes
WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
Refer to Power Distribution for schematic and connector information.
Normal Operation and Fault Conditions
When the ignition switch is turned to the ON position, a voltage signal is sent to the BCM. 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) and high current BJB fuse 3 (100A). The accessory relay receives voltage from high current BJB fuse 6 (70A).
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B10E7:12 | Ignition On Relay: Circuit Short to Battery | Sets when the BCM detects 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 | Sets when the BCM detects a short to voltage from the RJB accessory relay control circuit. When this DTC sets, the control side of the RJB accessory 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. |
| U300A:13 | Ignition Switch: Circuit Open | Sets during the on-demand self-test if the BCM detects no voltage from the ignition switch ON-designated circuit. |
Possible Causes
- Fuse
- Wiring, terminals or connectors
- Ignition relay
- RJB accessory relay
- Ignition switch
- BCM
Visual Inspection and Diagnostic Pre-checks
- Inspect the high current BJB fuses 3 (100A) and 6 (70A).
- Inspect the BJB fuse 23 (5A).