Pinpoint Test E: DTCs B299B and B29A5 - Suppressor Left/Right Circuit Short to Battery - Loop #1

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Police Option for schematic and connector information.

Normal Operation

The fire suppression system module (FSSM) checks all of the fire suppressor circuits for faults. If the FSSM detects a short to voltage on the LH fire suppressor squib 1 circuits, it stores DTC B299B in memory and illuminates the fire suppression system indicator. If the FSSM detects a short to voltage on the RH fire suppressor squib 1 circuits, it stores DTC B29A5 in continuous memory and illuminates the fire suppression system indicator.

DTC B299B (Suppressor Left Circuit Short to Battery - Loop #1) - sets when the FSSM detects a short to voltage on the left fire suppressor squib 1 circuits 2312 (LG) and 2313 (BK/WH). This DTC will cause the fire suppression system indicator to illuminate.

DTC B29A5 (Suppressor Right Circuit Short to Battery - Loop #1) - sets when the FSSM detects a short to voltage on the right fire suppressor squib 1 circuits 2310 (OG) and 2311 (DG). This DTC will cause the fire suppression system indicator to illuminate.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
FSSM

PINPOINT TEST E: DTCs B299B AND B29A5 - SUPPRESSOR LEFT/RIGHT CIRCUIT SHORT TO BATTERY - LOOP #1

WARNING: To reduce the risk of accidental deployment, never probe the connectors on the fire suppressors. Failure to follow this instruction may cause unintentional deployment of the suppressors, which may result in serious personal injury.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.

NOTE: The fire suppression system must be fully operational and free of faults before releasing the vehicle to the customer.

E1 CHECK FOR ON-DEMAND DTCs OR CONTINUOUS MEMORY DTCs
- Carry out the FSSM self-test.
- Were DTCs B299B or B29A5 retrieved as on-demand DTCs during the self-test?
1. YES : Go to E2.
2. NO : CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the key in the ignition lock cylinder frequently. REPEAT the self-test.

E2 CHECK THE FSSM

Key in OFF position.

WARNING: To reduce the risk of accidental deployment, do not use any memory saver devices when depowering the fire suppression system. Failure to follow this instruction may result in serious personal injury.

Disconnect the battery. Refer to BATTERY, MOUNTING & CABLES article.
Wait approximately 60 seconds to allow the fire suppression system backup power supply to deplete.
Disconnect: FSSM C3281a and C3281b
Disconnect: Inline C339
Connect the battery.
Key in ON position.

Measure the voltage between the inline C339, body harness side and ground as follows:

DTC	Connector-Pin	Circuit
B299B	C339-3	2312 (LG)
B299B	C339-4	2313 (BK/WH)
B29A5	C339-1	2310 (OG)
B29A5	C339-2	2311 (DG)

Is any voltage present?

YES : REPAIR the circuit in question. CONNECT the inline C339. CONNECT the battery. Go to E3.
NO : INSTALL a new FSSM. REFER to Fire Suppression System Module (FSSM) . Go to E3.

E3 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous memory DTCs recorded during Step E1.
- Were any continuous memory DTCs retrieved during Step E1?
1. YES : REFER to the FIRE SUPPRESSION SYSTEM MODULE (FSSM) DIAGNOSTIC TROUBLE CODE INDEX .
2. NO : CLEAR the DTCs. REPEAT the self-test.