- Engine:
- G3408C (S/N: BAZ2473-UP)
- G3412C (S/N: 6ZM2860-UP)
- G3508 (S/N: WPN1500-UP)
- G3512 (S/N: WPP1500-UP; WPR1500-UP)
- G3516 (S/N: WPT1500-UP; WPW1500-UP)
- G3516B (S/N: JEF1-UP)
- G3520B (S/N: TPC1-UP; GLF1-UP)
- G3412C (S/N: 6ZM2860-UP)
Introduction
Do not perform any procedure in this Special Instruction until you read this information and you understand this information.
This Special Instruction provides the procedure that is necessary for installing the nitrogen oxide sensor in G3400 and G3500 Engines. This includes the routing and the securing of the sensor harness.
Tools Needed
| Tools Needed |
| 4C-9594 Wrench (1/2 inch) |
| 2P-5496 Crowfoot Socket (7/8 inch) |
| 6V-6193 Diagonal Cutter |
| 9U-5019 Torque Wrench |
Removal
- Turn the Engine Control Switch to the "OFF/RESET" position. Switch the circuit breaker for the Electronic Control Module (ECM) to "OFF".
- Carefully cut off both existing tie-wraps near the sensor control unit with a 6V-6193 Diagonal Cutter .
 | |
| Illustration 1 | g01394281 |
(1) Tie-wraps | |
- Cut off tie-wrap (1) at support bracket (2) for the harness near the sensor control unit with a diagonal cutter. Carefully cut off existing tie-wrap (1) at support bracket (2) for the harness near the adapter ring for the exhaust.
 | |
| Illustration 2 | g01394629 |
Typical example (1) Tie-wraps (2) Support bracket | |
- Disconnect the 8-pin Deutsch connector of the sensor control unit from the engine harness.
 | |
| Illustration 3 | g01768696 |
8-pin Deutsch connector | |
- Loosen hex nut (3) that holds sensor (4) onto mounting ring (5) for the exhaust. Remove the sensor.
 | |
| Illustration 4 | g01394639 |
(3) Hex nut (4) Sensor (5) Mounting ring for the exhaust | |
- Loosen and remove 7.94 mm (5/16 inch) nuts (6) and washers (8) from the cover for the sensor control unit (7). Retain the nuts and the washers.
 | |
| Illustration 5 | g01394641 |
(6) 7.94 mm (5/16 inch) nuts (7) Cover for the sensor control unit | |
 | |
| Illustration 6 | g01774418 |
(6) Nuts (7) Cover for the sensor control unit (8) Washers (9) Spacers (10) Harness to the sensor (11) Sensor control unit (12) Mounting posts (13) Mounting plate (14) 8-pin Deutsch connector | |
- Remove the cover for sensor control unit (7). Retain the cover.
- Remove spacers (9) from the pan head screws. Retain the spacers.
- Remove sensor control unit (11) from mounting posts (12).
Installation
- Install the new sensor control unit (6) onto the two mounting posts (7). Verify that the sensor control unit is flush with mounting plate (8) .
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| Illustration 7 | g01774554 |
(1) Nuts (2) Cover for the sensor control unit (3) Washers (4) Spacers (5) Harness to the sensor (6) Sensor control unit (7) Mounting posts (8) Mounting plate (9) 8-pin Deutsch connector | |
- Place two spacers (4) onto the mounting posts (7). Install cover (2) for the sensor control unit (6). The cover has a slot that is located over the pin on the mounting plate (8). This slot ensures that the cover for the sensor control unit will align properly onto the mounting plate .
- Place washers (3) and the 7.94 mm (5/16 inch) nuts (1) onto the mounting posts (7). Tighten the nuts until the nuts are barely snug. This will allow movement of the cover for the sensor control unit.
- Slide one of the tie-wraps (15) over mounting port (20) that connects the ECM to the sensor control unit. Slide the other tie-wrap over the mounting port of the sensor (17). Ensure that the tie-wraps go around metal tabs (19) on cover (2). Pull the tab in order to tighten the tie-wrap as firmly as possible.
 | |
| Illustration 8 | g01769313 |
(15) Tie-wrap (16) Mounting ring for the exhaust (engine) (17) Mounting port for the sensor (2) Cover for the sensor control unit (19) Tabs (20) Mounting port for the ECM | |
- Tighten the 7.94 mm (5/16 inch) nuts.
Torque ... 25 ± 6 N·m (18.4 ± 4.4 lb ft)
- Insert the sensor into the mounting ring for the exhaust (16). Tighten the hex nut.
Torque ... 50 ± 5 N·m (36.9 ± 3.7 lb ft)
- Secure the harness to the uppermost clip. Use one of the provided tie-wraps. Ensure that the connecting clip of the tie-wraps are on the outside of the clip. Verify that the slack in the harness between the end of the sensor and the point of support matches the recommended slack that is listed in Table 2.
Note: The slack in the harness is crucial to the service life of the sensor. Make sure that the slack is the recommended measurement.
- Pull the sensor harness straight from the sensor control unit. Measure the distance between the support bracket and the harness connection to the sensor. Ensure that the measurement is 135 mm (5.31 inch) or 190 mm (7.48 inch). Refer to Table 2.
- Secure the sensor harness with a tie-wrap. Pull the tab in order to tighten the tie-wrap as firmly as possible.
Note: Leave the sensor harness loose. Leave an arc of slack so that there is not any pull on the sensor.
- Secure the sensor harness to the lower clip. Use one of the provided tie-wraps. Ensure that the connecting clip of the tie-wraps are on the outside of the clip. Verify that the slack in the harness between the end of the sensor and the point of support matches the recommended slack that is listed in Table 2.
- Secure the sensor harness with a tie-wrap. Pull the tab in order to tighten the tie-wrap as firmly as possible.
- Reconnect the 8-pin Deutsch connector from the sensor control unit to the engine harness.
| Engine |
Serial Number | Slack In Harness (Dimension B) (1) | Slack In Harness (Dimension A) (2) | Illustration |
| G3408 | (S/N: BAZ1) | 110 mm (4.33 inch) |
135 mm (5.3150 inch) |
10 |
| G3412 | (S/N: 6ZM1) | 10 | ||
| G3508 | (S/N: WPN01500) | 11 | ||
| G3512 | (S/N: WPP1) | 12 | ||
| G3512 | (S/N: WPR1) | 12 | ||
| G3516 | (S/N: WPT1) | 12 | ||
| G3516 | (S/N: WPW1) | 12 | ||
| G3516 | (S/N: JEF1) | 13 | ||
| G3520 | (S/N: GLF1) | 190 mm (7.4803 inch) |
14 | |
| G3520 | (S/N: TPC1) | 14 |
| ( 1 ) | The distance of the slack in the harness that is between the sensor control unit and the support bracket |
| ( 2 ) | The distance of the slack in the harness that is between the sensor and the support bracket |
 | |
| Illustration 9 | g01770538 |
(1) Slack in the harness ("A") (2) Slack in the harness ("B") | |
Reference
Use the following illustrations to reference the correct measurements.
G3408 and G3412
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| Illustration 10 | g01770753 |
(1) Mounting ring for the exhaust (2) Sensor (3) Harness (4) Slack in the harness (5) Support clip (6) Tie-wraps (7) Cover for the sensor control unit (8) Support bracket | |
G3508
 | |
| Illustration 11 | g01770913 |
(1) Mounting ring for the exhaust (2) Sensor (3) Sensor harness (4) Support clip for the harness (5) Mounting port for sensor (6) Cover for the sensor control unit (7) Tie-wraps (8) Slack in the harness | |
G3512 and G3516
 | |
| Illustration 12 | g01770994 |
(1) Mounting ring for the exhaust (2) Sensor (3) Slack in the harness (4) Tie-wraps (5) Sensor harness (6) Mounting port for sensor (7) Cover for the sensor control unit | |
G3516 ULB
 | |
| Illustration 13 | g01773680 |
(1) Mounting ring for the exhaust (2) Sensor (3) Slack in the harness (4) Support clip for the harness (5) Sensor harness (6) Mounting port for sensor (7) Cover for the sensor control unit | |
G3520
 | |
| Illustration 14 | g01773016 |
(1) Mounting ring for the exhaust (2) Sensor (3) Slack in the harness (4) Sensor harness (5) Support clip for the harness (6) Tie-wraps (7) Cover for the sensor control unit | |