Pinpoint Test J: DTC B2792 - Cross Link Between Firing Loops

WARNING: This page is about a different car, the 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(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.

J1 CHECK FOR A HARD OR INTERMITTENT DTC
WARNING: To reduce the risk of accidental deployment, never probe the connectors on the fire suppressors. Failure to follow this instruction may result in personal injury.
- Enter the following diagnostic mode on the scan tool: Retrieve/Record/Flag Continuous DTCs.
- Enter the following diagnostic mode on the scan tool: On-Demand Self-Test.
- Was DTC B2795 retrieved during the on-demand self-test?
Yes : This is a hard fault. The fault condition is still present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self-test. GO to J2.

No : This is an intermittent fault. The fault condition is not present at this time. CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition lock cylinder frequently. REPEAT the self-test.

J2 CHECK THE FSM FOR CROSSLINK BETWEEN #1 FIRING LOOPS

Key in OFF position.

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

Disconnect the battery. Refer to BATTERY, MOUNTING AND CABLES .
Wait approximately 60 seconds to allow the fire suppression module (FSM) back-up power supply to discharge.
Disconnect: FSM C3281a.

Measure the resistance between FSM C3281a pins, component side as follows:

FSM PIN REFERENCE

FSM C3281a Pin (LH Loop)	FSM C3281a Pin (RH Loop)
4	12
4	13
5	12
5	13

Are the resistances greater than 10,000 ohms?

Yes : GO to J3.

No : INSTALL a new FSM. REFER to FIRE SUPPRESSION MODULE . GO to J6.

J3 CHECK THE BODY HARNESS CIRCUITS FOR CROSSLINK

Connect: FSM C3281a.
Disconnect: Inline C339.

Measure the resistance between the inline C339 pins, body harness side as follows:

C339 PIN REFERENCE

Inline C339 Pin (LH Loop)	Inline C339 Pin (RH Loop)
3	1
3	2
4	1
4	2

Are the resistances greater than 10,000 ohms?

Yes : GO to J4.

No : REPAIR the circuits in question. CONNECT the inline C339. CONNECT the battery. GO to J6.

J4 CHECK THE LH FIRE SUPPRESSORS
- Connect: Inline C339.
- Disconnect: LH Fire Suppressor C4317.
- Connect the battery.
- Enter the following diagnostic mode on the scan tool: On-Demand Self-Test.
  NOTE: DTCs B299A and B299F are expected to be retrieved when the self-test is performed with the LH Fire Suppressor C4317 disconnected. These DTCs can be cleared once all the fire suppression connections are restored. If DTCs B299A or B299F are retrieved with all the fire suppression connections restored, refer to the FIRE SUPPRESSION MODULE (FSM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
- Was DTC B22B5 retrieved during the on-demand self-test?
Yes : DISCONNECT the battery. CONNECT the LH fire suppressor C4317. GO to J5.

No : INSTALL a new LH fire suppressor. REFER to FIRE SUPPRESSOR . GO to J6.
J5 CHECK THE LH FIRE SUPPRESSORS
- Disconnect: RH Fire Suppressor C4317.
- Connect the battery.
- Enter the following diagnostic mode on the scan tool: On-Demand Self-Test.
  NOTE: DTCs B29A9 and B29A4 are expected to be retrieved when the self-test is performed with the RH Fire Suppressor C4316 disconnected. These DTCs can be cleared once all the fire suppression connections are restored. If DTCs B29A9 or B29A4 are retrieved with all the fire suppression connections restored, refer to the FIRE SUPPRESSION MODULE (FSM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
- Was DTC B22B5 retrieved during the on-demand self-test?
Yes : INSTALL a new fire suppression system harness (14C369). GO to J6.

No : INSTALL a new RH fire suppressor. REFER to FIRE SUPPRESSOR . GO to J6.
J6 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous DTCs recorded during Step J1.
- Were any additional continuous DTCs retrieved during Step J1 ?
Yes : GO to the FIRE SUPPRESSION MODULE (FSM) DIAGNOSTIC TROUBLE CODE (DTC) TABLE to continue diagnosis of the fire suppression system.

No : CLEAR the DTCs. REPEAT the self-test.