Failure of the Control of the Solenoid 1 of the Fuel Return Valve on Channel A, Engine 1

TASK 73-20-00-810-905-A
Failure of the Control of the Solenoid 1 of the Fuel Return Valve on Channel A, Engine 1

1. Possible Causes

ECU [4000KS]
fuel return valve
harness J7

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	BRUSH - BRISTLED

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2011)	stoddard solvent

C. Referenced Information

REFERENCE	DESIGNATION
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 73-21-50-000-040	Removal of the HJ7 Harness for SAC Engines
AMM 73-21-50-210-002	Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-040	Installation of the HJ7 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
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)

3. Fault Confirmation
Subtask 73-20-00-710-206-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the FADEC 1A on the ground (with engine non motoring) AMM 73-29-00-710-040.

4. Fault Isolation
Subtask 73-20-00-810-173-A ** ON A/C NOT FOR ALL

A. The fault is generated when the ECU detects an open circuit or a short to ground on the fuel return valve solenoid for first level cooling or on associated electrical harness.
(1) If the test does not give the maintenance message J7, FRV(SOL 1), ECU or if the fault is repetitive:

Inspect the harness J7 and associated connectors to the fuel return valve and ECU for sign of looseness, damage or contamination ASM 732518.
Pay particular attention on pins 4 and 5 at the connector to the ECU and at pins 1 and 2 at the connector to the fuel return valve.
Re-tighten, clean or replace harness as required.

(a) If no defect is found either or on the harness or the connector no further action is due.
(b) If the fault continues or is repetitive:

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

Replace the harness J7 AMM 73-21-50-000-040 and AMM 73-21-50-400-040.

(d) If the fault continues:

Replace the ECU AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

(2) If the test gives the maintenance message J7, FRV(SOL 1), ECU:

disconnect the harness J7 from the ECU.
do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
if you find damage, repair or replace as required.
clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
do a resistance check on the harness J7 between:
. pins 4 and 5 (18 to 38 ohms)
. pins 4 and 1 (> 10 megohms)
. pin 4 and the ground (> 10 megohms).

(a) If the resistance values are in the specified limits:

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

(b) If the resistance values are out of the specified limits:

disconnect the harness J7 from the fuel return valve.
do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
if you find damage, repair or replace as required.
clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
do a resistance check between:
. pins 1 and 2 (18 to 38 ohms)
. pin 1 and the ground (> 10 megohms)

1 If the resistance values are out of the specified limits:

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

2 If the resistance values are in the specified limits:

replace the harness J7 AMM 73-21-50-000-040 and AMM 73-21-50-400-040.

Subtask 73-20-00-710-207-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:35:26 UTC