Heated Oxygen Sensor (HO2S) Wiring Repairs

Tools Required 

J-38125 Terminal Repair Kit

Use duraseal splice sleeves to form a one-to-one splice on all types of insulation except tefzel and coaxial. Use duraseal splice sleeves where there is special requirements such as moisture sealing. Follow the instructions below in order to splice copper wire using duraseal splice sleeves.

1. Open the harness.
   • If the harness is taped, remove the tape.
   • To avoid wiring insulation damage, use a sewing ripper in order to cut open the harness.
   • If the harness has a black plastic conduit, pull out the desired wire.
2. Cut the wire.
   • Cut as little wire off the harness as possible.
   • Ensure that each splice is at least 40 mm (1.5 in) away from other splices, harness branches and connectors. This helps prevent moisture from bridging adjacent splices and causing damage.
Fig 1: Proper Crimping Of Solderless Connector
Courtesy of GENERAL MOTORS CORP.
3. Select the proper size and type of wire.
   • The wire must be of equal or greater size than the original.
   • The wires insulation must have the same or higher temperature rating (4).
     • Use general purpose insulation for areas that are not subject to high temperatures.
     • Use a cross-linked polyethylene insulated wire for areas where high temperatures are expected.
       IMPORTANT: Use cross-linked polyethylene wire to replace PVC, but do not replace cross-linked polyethylene with PVC.
       Cross-linked polyethylene wire is not fuel resistant. Do not use to replace wire where there is the possibility of fuel contact.
4. Strip the insulation.
   • Select the correct size opening in the wire stripper or work down from the largest size.
   • Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be spliced (1).
5. Select the proper duraseal splice sleeve (2) and the required crimp nest tool, refer to the Crimp and Seal Splice Table.
6. Place the duraseal splice sleeve in the J-38125-8 (12085115) crimp tool nest so that the crimp falls at point 1 on the splice.
7. Close the hand crimper handles slightly in order to hold the duraseal splice sleeve firmly in the proper crimp tool nest.
8. Insert the wires into the duraseal splice sleeve until the wire hits the barrel stop. The splice sleeve has a stop in the middle of the barrel in order to prevent the wire from passing through the splice (3).
9. Close the handles of the J-38125-8 (12085115) until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve.
10. Shrink the insulation around the splice.
    • Using the heat torch apply heat to the crimped area of the barrel.
    • Gradually move the heat barrel to the open end of the tubing.
      • The tubing will shrink completely as the heat is moved along the insulation.
      • A small amount of sealant will come out of the end of the tubing when sufficient shrinkage is achieved.

J-38125 Terminal Repair Kit

1. Open the harness.
   • If the harness is taped, remove the tape.
   • To avoid wiring insulation damage, use a sewing ripper in order to cut open the harness.
   • If the harness has a black plastic conduit, pull out the desired wire.
2. Cut the wire.
   • Cut as little wire off the harness as possible.
   • Ensure that each splice is at least 40 mm (1.5 in) away from other splices, harness branches and connectors. This helps prevent moisture from bridging adjacent splices and causing damage.
3. Select the proper size and type of wire.
   • The wire must be of equal or greater size than the original (except fusible link).
   • The wire's insulation must have the same or higher temperature rating.
     • Use general purpose insulation for areas that are not subject to high temperatures.
     • Use a cross-linked polyethylene insulated wire for areas where high temperatures are expected.
       IMPORTANT: Use cross-linked polyethylene wire to replace PVC, but do not replace cross-linked polyethylene with PVC.
       Cross-linked polyethylene wire is not fuel resistant. Do not use to replace wire where there is the possibility of fuel contact.
4. Strip the insulation.
   • Select the correct size opening in the wire stripper or work down from the largest size.
   • Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be spliced.
5. Select the proper clip to secure the splice. Follow the instructions in the J-38125 in order to determine the proper clip size crimp tool and anvil.
6. Overlap the 2 stripped wire ends and hold them between thumb and forefinger.
Fig 2: Centering Splice Clip Over Stripped Wires
Courtesy of GENERAL MOTORS CORP.
7. Center the splice clip (2) over the stripped wires (1) and hold the clip in place.
   • Ensure that the wires extend beyond the clip in each direction.
   • Ensure that no insulation is caught under the clip.
Fig 3: Centering Crimp Tool Over Splice Clip & Wires
Courtesy of GENERAL MOTORS CORP.
8. Center the crimp tool over the splice clip and wires.
9. Apply steady pressure until the crimp tool closes.

   Ensure that no strands of wire are cut.

Fig 4: Crimping Splices
Courtesy of GENERAL MOTORS CORP.
10. Crimp the splice on each end (2).
Fig 5: Applying Solder To Back Of Clip Opening
Courtesy of GENERAL MOTORS CORP.
11. Apply 60/40 rosin core solder to the opening in the back of the clip. Follow the manufacturer's instructions for the solder equipment.
Fig 6: Applying Electrical Tape
Courtesy of GENERAL MOTORS CORP.
12. Tape the splice. Roll on enough tape in order to duplicate the thickness of the insulation on the existing wires.
Fig 7: Applying Additional Tape To Wire
Courtesy of GENERAL MOTORS CORP.
13. Additional tape can be applied to the wire if the wire does not belong in a conduit or another harness covering. Use a winding motion in order to cover the first piece of tape.

J-38125 Terminal Repair Kit

If the heated oxygen sensor pigtail wiring, connector, or terminal is damaged the entire oxygen sensor assembly must be replaced. Do not attempt to repair the wiring, connector, or terminals. In order for the sensor to function properly it must have a clean air reference. This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of the air reference and degrade oxygen sensor performance.

The following guidelines should be used when servicing the heated oxygen sensor:

• Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor, causing poor performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems.
• Neither the sensor nor vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire.
• Do not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wire sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will also cause poor engine performance.
• To prevent damage due to water intrusion, be sure that the peripheral seal remains intact on the vehicle harness connector.

The engine harness may be repaired using the J-38125 .