Failure of the FRV of the Engine 2 in the Open Position, on Channel B

TASK 73-10-00-810-816-A
Failure of the FRV of the Engine 2 in the Open Position, on Channel B

1. Possible Causes

harness J8
fuel return valve
ECU [4000KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 71-00-00-710-002	Wet Motoring Check
AMM 73-11-50-000-002	Removal of the Fuel Return Valve (FRV)
AMM 73-11-50-400-002	Installation of the Fuel Return Valve
AMM 73-21-50-000-041	Removal of the HJ8 Harness for SAC Engines
AMM 73-21-50-400-041	Installation of the HJ8 Harness for SAC Engines
AMM 73-21-60-000-001	Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001	Installation of the Electronic Control Unit (ECU)
ASM 732518

3. Fault Confirmation
Subtask 73-10-00-710-078-A ** ON A/C NOT FOR ALL

A. Not applicable.

4. Fault Isolation
Subtask 73-10-00-810-069-A ** ON A/C NOT FOR ALL

A. The fault is generated when the fuel return valve fails to reach the closed position when commanded by the ECU.
(1) Inspect the harness J8 and associated connector for sign of damage or contamination ASM 732518.
Pay particular attention to pins 14 and 31 on the harness connector to the ECU and to pins 3 and 4 on the harness connector to the fuel return valve. Defective contacts on those connectors may give an erroneous indication of the fuel return valve position switches.
(2) If damage is found:

replace the harness J8 AMM 73-21-50-000-041 and AMM 73-21-50-400-041.

(3) If nothing is found:

replace the fuel return valve AMM 73-11-50-000-002 and AMM 73-11-50-400-002.

(4) If the fault continues:

replace the harness J8 AMM 73-21-50-000-041 and AMM 73-21-50-400-041.

(5) If the fault continues:

replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

Subtask 73-10-00-710-079-A ** ON A/C NOT FOR ALL

B. Do a wet motoring test of the engine AMM 71-00-00-710-002 and check that the fault does not duplicate.

[Rev.8 from Aug 2018] 2026.04.04 04:35:14 UTC