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PCM Connector: Black (C4) 1996-1997
To navigate to a different PCM connector, use the links below:
| C4 (Grey) PCM 24 Pin Connector | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | Dark Green w/ White stripe | Fuel Pump Relay Control |
| 2 | --- | Empty |
| 3 | Dark Green w/ White stripe | VSS Output Signal (TCCM, Radio, Cruise) |
| 4 | Dark Green | VSS Output Signal (speedometer) |
| 5 | Brown w/ White stripe | Malfunction Indicator Light (MIL) Control |
| 6 <-> | Dark Blue | Auxiliary Fan Relay (1997 only) |
| 6 <-> | --- | Empty (1996 only) |
| 7 | --- | Empty |
| 8 | --- | Empty |
| 9 | --- | Empty |
| 10 | Purple | Brake Signal |
| 11 | Purple | Serial Data |
| 12 | --- | Empty |
| 13 | Brown | 12 V Ignition Feed |
| 14 | --- | Empty |
| 15 | Tan w/ Black stripe | Shift Control Lamp |
| 16 | --- | Empty |
| 17 | --- | Empty |
| 18 | Pink | 12 Volt Ignition Feed |
| 19 | Black w/ White stripe | 4WD Engaged Signal (Automatic Transmission Only) |
| 20 | --- | Empty |
| 21 | --- | Empty |
| 22 | --- | Empty |
| 23 | Gray w/ Black | Transfer Case Hi Low Switch |
| 24 | Light Blue w/ Black stripe | Cruise Engaged Signal |
Safety Precautions
Here are some very important safety precautions when testing the wires coming out of the PCM connectors.
- If one or any of the wires on your GM vehicle DO NOT match the color stated in the Pin Out Charts, then you should not use the Pin Out charts in this article. Why? Because this is the clearest indication that these ARE NOT the Connector Pin Out Charts for your particular vehicle.
- Never probe the front of the connector.
- You should use a wire piercing probe and probe the wire a few inches away from the connector.
- To see what this tool looks like: Wire Piercing Probe.
- You should use a back-probe.
- You should use a wire piercing probe and probe the wire a few inches away from the connector.
- This is a FLASH unit and requires reprogramming if replaced with a new one or used one.
- Read the Disclaimer.
If this info saved the day, buy me a beer!
