Pinpoint Test M: The Fire Suppression System Indicator Is Always On (Police Vehicles Only)
Instrumentation, Message Center and Warning Chimes
Pinpoint Test M: The Fire Suppression System Indicator Is Always On (Police Vehicles Only)
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
If the Fire Suppression System Module (FSSM) detects a concern with any of the fire suppression system components, the fire suppression indicator illuminates and a DTC is logged.
The FSSM is hardwired to the Instrument Cluster (IC) through circuit 2318 (LG/RD), and is grounded through circuit 1203 (LG/RD). If a fault occurs in the fire suppression system, DTCs are set and the FSSM removes the ground circuit 2318 (LG/RD), sending the voltage high to the IC, illuminating the fire suppression system indicator.
- DTC B1921 (Air Bag Diagnostic Monitor Ground Circuit Open) - a continuous and on-demand DTC that sets if the FSSM detects an open or high resistance on the ground circuit 1203 (BK/LB).
- DTC B29B3 (Fire Suppression Indicator Lamp Circuit Failure) - a continuous and on-demand DTC that sets if the FSSM detects an open on the fire suppression indicator lamp circuit 2318 (LG/RD).
- DTC B29B4 (Fire Suppression Indicator Lamp Circuit Short to Battery) - sets if the FSSM detects a short to voltage on the fire suppression indicator lamp circuit 2318 (LG/RD) during prove-out at key-on, or when the fire suppression indicator lamp is activated.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- FSSM
- IC
PINPOINT TEST M: THE FIRE SUPPRESSION SYSTEM INDICATOR IS ALWAYS ON (POLICE VEHICLES ONLY)
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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M1 RETRIEVE THE RECORDED DTCs FROM THE FSSM SELF-TEST
- Check for recorded FSSM DTCs from the self-test.
- Are any DTCs recorded?
Yes
If DTC B1921 is recorded, GO to M6.
If DTC B29B3 is recorded, GO to M5.
If DTC B29B4 is recorded, GO to M4.
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to M2.
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M2 CARRY OUT THE IC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC all lamps (ALL_LAMP) active command on and off. Observe the fire suppression system indicator.
- Does the fire suppression system indicator illuminate when selected on, and turn off when selected off?
Yes
GO to M3.
No
GO to M7.
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M3 CHECK THE FIRE SUPPRESSION SYSTEM INDICATOR FOR CORRECT OPERATION
- Ignition OFF.
- Disconnect the battery. Refer to Battery.
- Wait approximately 60 seconds to allow the FSSM back-up power to discharge.
- Disconnect: FSSM C3281a.
- Connect a fused jumper wire between the FSSM C3281a-6, circuit 2318 (LG/RD), harness side and ground.
- Connect the battery.
- Ignition ON.
- Does the fire suppression system indicator turn off?
Yes
GO to M8.
No
GO to M7.
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M4 CHECK CIRCUIT 2318 (LG/RD) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: FSSM C3281a.
- Disconnect: IC C2220.
- Ignition ON.
- Measure the voltage between the IC C2220-10, circuit 2318 (LG/RD), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to M7.
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M5 CHECK CIRCUIT 2318 (LG/RD) FOR AN OPEN
- Ignition OFF.
- Disconnect: FSSM C3281a.
- Disconnect: IC C2220.
- Measure the resistance between the IC C2220-10, circuit 2318 (LG/RD), harness side and the FSSM C3281a-6, circuit 2318 (LG/RD), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to M7.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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M6 CHECK CIRCUIT 1203 (BK/LB) FOR AN OPEN
- Ignition OFF.
- Disconnect: FSSM C3281a.
- Measure the resistance between the FSSM C3281a-7, circuit 1203 (BK/LB), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to M7.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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M7 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC connector and make sure it seats correctly.
- Verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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M8 CHECK FOR CORRECT FSSM OPERATION
- Disconnect the battery. Refer to Charging System.
- Wait approximately 60 seconds to allow the FSSM back-up power to discharge.
- Disconnect the FSSM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the FSSM connector and make sure it seats correctly.
- Connect the battery.
- Verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new FSSM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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