LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2000 >> Excursion 7.3 F, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1471 (Supplemental Restraint System) >> Diagnosis And Testing >> Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) >> Pinpoint Test - Occupant Classification System Module (OCSM) >> Pinpoint Test AD: DTC B2909 >> Normal Operation
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Normal Operation

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The Belt Tension Sensor (BTS) operates in conjunction with the Occupant Classification Sensor (OCS) system. The OCS  system interprets a variable voltage signal provided by the BTS  to identify the possible presence of a child safety seat in the front passenger seat. The voltage output of the BTS  is proportional to the amount of tension applied to the sensor by the belt, no-tension low voltage (approximately 0.95 volt), high-tension high voltage (approximately 3.8 volts).

The Occupant Classification System Module (OCSM) monitors the BTS  and circuitry for faults. If a fault is detected, the OCSM  will store DTC B2909 in memory and send a message to the Restraints Control Module (RCM). The RCM  will store DTC B00A0:09 in memory and send a message to the Instrument Cluster (IC) module to illuminate the air bag warning indicator.

ITEM DESCRIPTION

Fault PIDs (1) Description Fault Trigger Condition
2909_29_OD and 2909_29_CM Front Passenger Side Belt Tension Sensor Short to Ground When the OCSM  senses a short to ground on the BTS  circuits, a fault will be indicated.
2909_31_OD and 2909_31_CM Front Passenger Side Belt Tension Sensor Circuit Fault When the OCSM  senses a failure on the BTS  circuits, a fault will be indicated.
2909_30_OD and 2909_30_CM Front Passenger Side Belt Tension Sensor Circuit Open When the OCSM  senses an open on the BTS  circuits, a fault will be indicated.
2909_28_OD and 2909_28_CM Front Passenger Side Belt Tension Sensor Circuit Short to Battery When the OCSM  senses a short to voltage on the BTS  signal circuit, a fault will be indicated.
(1) Fault PIDs that end in OD indicate on-demand status and are associated with DTC B2909. Fault PIDs that end in CM indicate continuous memory status and are associated with DTC B2909.

This pinpoint test is intended to diagnose the following: 

scientia non olet · About LEMON Manuals