Pinpoint Test E: DTCs B299B And B29A5
Fire Suppression System
Pinpoint Tests
Pinpoint Test E: DTCs B299B And B29A5
Refer to Wiring Diagram Set 96, Police Option for schematic and connector information. Diagrams By Number
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 and 2313. This DTC causes the LH 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 RH fire suppressor squib 1 circuits 2310 and 2311. This DTC causes 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
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.
WARNING: To prevent the risk of inadvertent deployment of the fire suppression system (FSS), never defeat wiring connector shorting bars or remove the connectors. All fire suppressor wiring connectors incorporate shorting bars to reduce the potential of static electricity charges causing unintended suppressor activation. Failure to follow this warning may result in serious personal injury or death.
NOTICE: 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. Inspection and Verification
NOTE: The fire suppression system must be fully operational and free of faults before releasing the vehicle to the customer.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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E1 CHECK FOR ON-DEMAND OR CONTINUOUS MEMORY DTCs
- Carry out the FSSM self-test.
- Is DTC B299B or DTC B29A5 retrieved as an on-demand DTC during the self-test?
Yes
GO to E2.
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.
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E2 CHECK THE FSSM
- Ignition OFF.
- 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: Negative Battery Cable.
- Wait approximately 60 seconds to allow the fire suppression system backup power supply to deplete.
- Disconnect: FSSM C3281a.
- Connect: Negative Battery Cable.
- Ignition ON.
- Measure the voltage between the FSSM C3281a, body harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CONNECT the inline C339. CONNECT the negative battery cable. GO to E3.
No
GO to E4.
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E3 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous memory DTCs recorded during Step E1.
- Were any continuous memory DTCs retrieved during Step E1?
Yes
REFER to DTC Charts. Diagnostic Trouble Code Tests and Associated Procedures
No
CLEAR the DTCs. REPEAT the self-test.
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E4 CHECK FOR CORRECT FSSM OPERATION
- Disconnect all the FSSM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the FSSM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new FSSM. REFER to Fire Suppression System Module (FSSM) Service and Repair. REPEAT the self-test.
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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