Special wiring repair procedures have been developed for use on the Supplemental Inflatable Restraint (SIR) system due to the sensitive nature of the circuitry. You must follow these specific procedures and instructions when working with the SIR system wiring, and the wiring components (such as connectors and terminals).

Essential tool kit J-38125 Terminal Repair Kit contains special sealed splices for use in repairing SIR system wiring. A special crimping tool, heat torch, and instruction manual for these splices are also included.

Two critical features of the sealed splices are a special heat shrink sleeve with sealing adhesive to produce an environmentally sealed splice and a cross hatched (knurled) core crimp to provide necessary contact integrity for the sensitive, low energy circuits.

The J-38125 Terminal Repair Kit also serves as a generic terminal repair kit. The kit contains a large sampling of common GM electrical terminals and the correct tools to attach them to wires and remove them from connectors. The terminals in the kit are not to be used to replace damaged SIR system terminals unless specifically indicated by the terminal package. The DERM terminal repair assembly pack is included in the kit for SIR use.

If damage occurs to any connector or terminal in the SIR wire harness (except pigtails), you must repair the connector using one of the connector repair assembly packs. These kits include an instruction sheet and the sealed splices which you will use to splice the new wires, the connector, and the terminals to the harness. You must use the splice crimping tool from J-38125 Terminal Repair Kit, to apply these splices.

The terminals in the SIR system are made of a special metal to provide necessary contact integrity for the sensitive, low energy circuits. You must use the terminals found in the connector repair assembly packs. Do not substitute any other terminals for those in the assembly packs.

If damage occurs to the individual terminals on the DERM connector, repair them using the DERM terminal repair assembly pack. If damage occurs to the individual terminals on any other SIR connection, you must repair the entire connection using the appropriate connector repair assembly pack. It may be necessary to replace the entire SIR wiring harness.

If damage occurs to the wiring pigtail (a wire or wires attached directly to the device, not by a connector), you must replace the entire component (with pigtail). Pigtail component include the inflatable restraint steering wheel module coil.

Tools Required

J-38125 Terminal Repair Kit.

If damage occurs to any wire except the pigtail, you should repair the wire by splicing in a new section of wire of the same gauge size (0.5, 0.8, 1.0 mm etc.). You must use the sealed splices and splice crimping tool from J-38125 Terminal Repair Kit. You must use the following wiring repair procedures to ensure the integrity of the sealed splice application.

Step One: Open the Harness

Remove any tape from the harness. To avoid wire insulation damage, use a sewing seam ripper (available from sewing supply stores) to cut open the harness. You may use the crimp and sealed splice sleeves on all types of insulation except tefzel and coaxial. You may only use the sleeves to form a one-to-one splice.

Step Two: Cut the Wire

Cut as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire in order to change the location of a splice.

You may have to adjust splice locations in order to ensure that each splice is at least 40 mm (1.5 inches) away from the other splices, harness branches, or connectors.

Notice: You must perform the following procedures in the listed order. Repeat the procedure if any wire strands are damaged. You must obtain a clean strip with all of the wire strands intact.

Step Three: Strip the Insulation

If you must add a length of wire to the existing harness, make sure to use the same size as the original wire.

To find the correct wire size, find the wire on the schematic. Then convert the metric size to the equivalent AWG size. You may also use an AWG wire gauge.

If unsure about the wire size, begin with the largest opening in the wire stripper and work down until achieving a clean strip of the insulation. Strip approximately 7.5 mm (0.313 inch) of insulation from each wire you intend to splice. Avoid nicking or cutting any of the strands. Avoid cutting any of the strands. Check the stripped wire for nicks or cut strands. If damage occurred to the wire, repeat this procedure after removing the damaged section.

Step Four: Select and Position the Splice Sleeve

Select the proper sealed splice sleeve according to wire size. See the following table for color coding of the splice sleeves, and the crimp tool nests.

Important: Refer to Wiring Repairs in Wiring Systems in order to determine the correct wire size for the circuit you are repairing. You must obtain this information in order to ensure circuit integrity.

Position the splice sleeve in the proper color nest of the Splice Crimp Tool from J-38125 Terminal Repair Kit. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest.

Step Five: Insert Wires Into Splice Sleeve and Crimp

Insert the wire into the splice sleeve until it hits the barrel stop.

Close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until you apply the proper amount of pressure to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice.

Step Six: 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. Shrink the tubing completely as you move the heat along the insulation. When you achieve sufficient shrinkage, a small amount of sealant will come out of the end of the tubing.

Apply a new splice (not sealed) from the J-38125 Terminal Repair Kit if damage occurs to any of the original equipment splices (three wires or more) in the SIR wiring harness. Carefully follow the instructions included in the kit for proper splice clip application.

The connector position assurance is a small plastic insert that fits through the locking tabs of all the SIR system electrical connectors. The CPA ensures that the connector halves cannot vibrate apart. You must have the CPA in place in order to ensure good contact between the SIR mating terminals.

The Terminal Position Assurance (TPA) insert resembles the plastic combs used in the control module connectors. The TPA keeps the terminal securely seated in the connector body. Do not remove the TPA from the connector body unless you remove a terminal for replacement.