Usage:
Introduction:
This instruction is for removal and installation of the 122-8840 Wiring Harness for the Speed/Timing Sensors on these engines. This harness is intended for service replacement of the section of the 122-8835 Wiring Harness that serves only the engine Speed/Timing Sensors.
Installation:
A. Remove The Failed Harness:
1. Locate the engine Speed/Timing Sensors below and inboard of the high-pressure hydraulic pump. Look at the back side of the timing gear on the left front side of the engine, as seen from the driver's seat (illustration 1). If an air compressor is installed, the sensors will be inboard of the compressor.
Illustration 1. M12 Bolt (1), Lower Speed Timing Sensor (2), Upper Speed Timing Sensor (3), tie wrap (4), two tie wraps (5), P2 harness side of 40-pin connector (6), J2 ECM side of 40-pin connector.
2. Remove the tie wraps from the Speed/Timing Sensor Harness. There will be one tie wrap (4) a few inches behind the sensors, a second tie wrap about ten inches aft from the back of the front cover, and a third tie wrap several inches aft of the second (5).
3. Remove the M12 Bolt (1), then remove the 119-4142 Speed/Timing Sensor Group (including the bracket) from the back of the front cover, with the harness still attached.
4. Move the sensors, connectors and harness aft and upward for better accessibility.
5. Squeeze the spring clip with thumb and fingers on both top and bottom of each connector and carefully remove the harness connectors from the speed/timing sensor group. Set the sensors aside.
6. On early production engines the 122-8835 Wiring Harness is one piece. If so, cut the speed/timing sensor wires where they emerge from the braid at the sensor end. On later engines, the harness is built in four separate segments.
7. Remove the 40-pin connector P2 from J2 on the ECM by unscrewing the M5 Allen Head Screw from the rear of J2.
8. Using the 121-9588 Deutsch Pin Removal Tool (medium blue, for #16 and #18 gage wires), remove the four pins from P2 (illustration 2). Insert the wire removal tool without twisting.
9. Remove the black wire from P2 pin-8, and the white wire from P2 pin-9 (from top sensor). Remove the yellow wire from P2 pin-3, and the blue wire from P2 pin-15 (from bottom sensor). Cut these wires where they emerge from the braid.
B. Install New 122-8840 Wiring Harness:
Illustration 2. P2 pin-8 (1), P2 pin-3 (2), P2 pin-9 (3), P2 pin-15 (4), P2 harness side of 40-pin connector (5), J2 ECM side of 40-pin connector (6), M5 Allen Head Screw (7).
1. Install harness in reverse order of removal. Plug the black wire into P2 pin-8, the white wire into P2 pin-9, the yellow wire into P2 pin-3, and the blue wire into P2 pin-15. (illustration 2). After inserting, use the 45 N (10 lb) pull test to verify that the connection is secure.
2. Blend the wires from the replacement harness in with all the other wires coming from P2 and install a tie wrap about three inches from P2.
3. Route the replacement speed/timing sensor service harness along with the old harness [which still contains the two wires going to the Injection Actuation Pressure Control Valve (IAPCV)] until forward of the second secured tie wrap. Be sure the wires are routed next to the block, between the block and the hydraulic pump oil feed tube.
4. Use tie wraps to bind the replacement harness to the old harness. Be sure new tie wraps are installed around both harnesses in the three locations that are secured to the block. Use as many additional unsecured tie wraps as necessary to bind the two harness sections tightly together. Do not attach tie wraps to individual wires. Attach tie wraps only to braided sections of harness.
| NOTICE |
|---|
It is especially important to replace the tie wrap nearest the sensors, to prevent sensor failure caused by vibration of loose sensor wires. |
5. Prior to installing the two sensors, lubricate the O-rings with engine oil. Push the dual speed/timing sensor assembly in until it is seated before installing the M12 Bolt. It should be possible to feel when the assembly is fully seated.
6. Tighten the M12 Bolt holding the 119-4142 Speed/Timing Sensor Group in place to 100 ± 20 N·m (75 ± 15 lb ft).
7. Reinstall P2 onto J2, and tighten the M5 Allen Head Screw from rear of J2 into P2 to 2.25 ± 0.25 N·m (20 ± 2 lb in).