Normal Operation

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

When the smart junction box (SJB) detects the multifunction switch in the LH TURN position, the SJB provides voltage through circuit CLS21 (BU/GN) to the LH front turn lamp (and the side repeater for Mariner). When the SJB detects the multifunction switch in the RH TURN position, the SJB provides voltage through circuit CLS25 (YE/VT) to the RH front turn lamp (and the side repeater for Mariner). Circuit GD120 (BK/GN) provides ground. The rear turn lamps are controlled utilizing the rear stoplamp circuitry.

DTC B2A27 (Right Front Turn Lamp Circuit Open) - is an on-demand DTC that sets when the SJB detects an open or short to voltage on the RH front turn lamp voltage supply circuit.

DTC B2A28 (Right Front Turn Lamp Circuit Short to Ground) - is a continuous and on-demand DTC that sets when the SJB detects a short to ground on the RH front turn lamp voltage supply circuit.

DTC B2A29 (Left Front Turn Lamp Circuit Open) - is an on-demand DTC that sets when the SJB detects an open or short to voltage on the LH front turn lamp voltage supply circuit.

DTC B2A2A (Left Front Turn Lamp Circuit Short to Ground) - is a continuous and on-demand DTC that sets when the SJB detects a short to ground on the LH front turn lamp voltage supply circuit.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Bulb holder
SJB