Loss of the Feedback Signal of the N1 Speed Sensor - Engine 1 - Channel B
TASK 77-10-00-810-816-A
Loss of the Feedback Signal of the N1 Speed Sensor - Engine 1 - Channel B
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Fault Confirmation
Subtask 77-10-00-710-080-A ** ON A/C NOT FOR ALL
Subtask 77-10-00-810-065-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:37:37 UTC
Loss of the Feedback Signal of the N1 Speed Sensor - Engine 1 - Channel B
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | BRUSH - BRISTLED |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP2011) | stoddard solvent |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 73-21-50-000-009 | Removal of the J10 Harness |
| AMM 73-21-50-000-043 | Removal of the HJ10 Harness for SAC Engines |
| AMM 73-21-50-210-001 | Visual Inspection of the Wiring Harness |
| AMM 73-21-50-210-002 | Visual Inspection of the Wiring Harnesses |
| AMM 73-21-50-400-009 | Installation of the J10 Harness |
| AMM 73-21-50-400-043 | Installation of the HJ10 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) |
| AMM 73-29-00-710-040 | Operational Test of the FADEC on the ground (with Engine Motoring) |
| AMM 77-11-10-000-001 | Removal of the N1 Speed Sensor |
| AMM 77-11-10-000-002 | Removal of the N1 Speed Sensor |
| AMM 77-11-10-400-001 | Installation of the N1 Speed Sensor |
| AMM 77-11-10-400-002 | Installation of the N1 Speed Sensor |
Subtask 77-10-00-710-080-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 1B on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault IsolationSubtask 77-10-00-810-065-A ** ON A/C NOT FOR ALL
A. The failure message is generated if channel B input from the N1 sensor is invalid or out of range.
(1) If the failure message N1 SENS, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SENS, J10, ECU is not confirmed but is repetitive:
1 If damage is found:
1 If damage is found:
1 If damage is found:
Subtask 77-10-00-810-065-B ** ON A/C NOT FOR ALL (1) If the failure message N1 SENS, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SENS, J10, ECU is not confirmed but is repetitive:
- disconnect J10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do a cleaning of the connector and receptacle using a BRUSH - BRISTLED with stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- replace the SENSOR-N1 ROTATIONAL SPD [4000EV] AMM 77-11-10-000-001 and AMM 77-11-10-400-001.
- replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the J10 harness AMM 73-21-50-000-009 and AMM 73-21-50-400-009.
- disconnect the J10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the N1 sensor (4000EV) (channel B) between:
. pins 1 and 2 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 1 and 3 (>5 kiloohms)
. pin 1 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 1 and 3 (>10 megohms)
. pin 1 and the ground (>10 megohms).
- replace the N1 sensor (4000EV) AMM 77-11-10-000-001 and AMM 77-11-10-400-001.
- connect the J10 harness to the N1 sensor.
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the J10 harness between:
. pins 16 and 17 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 16 and 6 (>5 kiloohms)
. pin 16 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 16 and 6 (>10 megohms)
. pin 16 and the ground (>10 megohms).
- replace the ECU (4000KS) AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the J10 harness AMM 73-21-50-000-009 and AMM 73-21-50-400-009.
A. The failure message is generated if channel B input from the N1 sensor is invalid or out of range.
(1) If the failure message N1 SNSR, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SNSR, J10, ECU is not confirmed but is repetitive:
1 If damage is found:
1 If damage is found:
1 If damage is found:
Subtask 77-10-00-810-065-C ** ON A/C NOT FOR ALL (1) If the failure message N1 SNSR, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SNSR, J10, ECU is not confirmed but is repetitive:
- disconnect J10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do a cleaning of the connector and receptacle using a BRUSH - BRISTLED with stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
- replace the SENSOR-N1 ROTATIONAL SPD [4000EV] AMM 77-11-10-000-001 and AMM 77-11-10-400-001.
- replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the J10 harness AMM 73-21-50-000-009 and AMM 73-21-50-400-009.
- disconnect the J10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the N1 sensor (4000EV) (channel B) between:
. pins 1 and 2 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 1 and 3 (>5 kiloohms)
. pin 1 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 1 and 3 (>10 megohms)
. pin 1 and the ground (>10 megohms).
- replace the N1 sensor (4000EV) AMM 77-11-10-000-001 and AMM 77-11-10-400-001.
- connect the J10 harness to the N1 sensor.
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the J10 harness between:
. pins 16 and 17 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 16 and 6 (>5 kiloohms)
. pin 16 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 16 and 6 (>10 megohms)
. pin 16 and the ground (>10 megohms).
- replace the ECU (4000KS) AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the J10 harness AMM 73-21-50-000-009 and AMM 73-21-50-400-009.
A. The failure message is generated if channel B input from the N1 sensor is invalid or out of range.
(1) If the failure message N1 SNSR, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SNSR, J10, ECU is not confirmed but is repetitive:
1 If damage is found:
1 If damage is found:
1 If damage is found:
Subtask 77-10-00-710-081-A ** ON A/C NOT FOR ALL (1) If the failure message N1 SNSR, J10, ECU is not confirmed:
(a) No maintenance action is required.
(2) If the failure message N1 SNSR, J10, ECU is not confirmed but is repetitive:
- disconnect HJ10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do a cleaning of the connector and receptacle using a BRUSH - BRISTLED with stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
- replace the SENSOR-N1 ROTATIONAL SPD [4000EV] AMM 77-11-10-000-002 and AMM 77-11-10-400-002.
- replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the HJ10 harness AMM 73-21-50-000-043 and AMM 73-21-50-400-043.
- disconnect the HJ10 harness from the N1 sensor (N1-B connector).
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the N1 sensor (4000EV) (channel B) between:
. pins 1 and 2 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 1 and 3 (>5 kiloohms)
. pin 1 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 1 and 3 (>10 megohms)
. pin 1 and the ground (>10 megohms).
- replace the N1 sensor (4000EV) AMM 77-11-10-000-002 and AMM 77-11-10-400-002.
- connect the HJ10 harness to the N1 sensor.
1 If damage is found:
- repair or replace as required.
- do the electrical resistance test through the HJ10 harness between:
. pins 16 and 17 (40 to 80 ohms)
for S/N different than 25451 and up:
. pins 16 and 6 (>5 kiloohms)
. pin 16 and the ground (>10 megohms)
for S/N 25451 and up:
. pins 16 and 6 (>10 megohms)
. pin 16 and the ground (>10 megohms).
- replace the ECU (4000KS) AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- replace the HJ10 harness AMM 73-21-50-000-043 and AMM 73-21-50-400-043.
B. Do the test given in Para. 3.A.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.