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The Powertrain Control Module (PCM) on the 2004 4.8L, 5.3L, and 6.0L V8 equipped Chevrolet Express and GMC Savana vans has two connectors. Each connector can be identified as:
- C1 Blue (80 Pin Connector).
- C2 Green (80 Pin Connector).
In this and following pages, you'll find the terminal pinouts for both PCM connectors.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- Chevrolet Express 1500 5.3L: 2004.
- Chevrolet Express 2500 4.8L, 5.3L, 6.0L: 2004.
- Chevrolet Express 3500 4.8L, 6.0L: 2004.
- GMC Savana 1500 5.3L: 2004.
- GMC Savana 2500 4.8L, 5.3L, 6.0L: 2004.
- GMC Savana 3500 4.8L, 6.0L: 2004.
NOTE: You can find other the PCM connector pinouts here:
- PCM Connector C1 And C2 Pin Out Charts (2003 V8 Chevrolet Express, GMC Savana)
- PCM Connector C1 And C2 Pin Out Charts (2005-2006 V8 Chevrolet Express, GMC Savana)
- PCM Connector C1 And C2 Pin Out Charts (2007 V8 Chevrolet Express, GMC Savana)
PCM Connector: C1 (Blue) - 2004 V8 Chevy Express/GMC Savana
| C1 (Blue) Terminals 1 - 40 | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | BLK/WHT | Chassis Ground |
| 2 | LT GRN | CKP Sensor 12 Volts Reference |
| 3 | PNK/BLK | Fuel Inj. #3 Control |
| 4 | LT GRN/BLK | Fuel Inj. #2 Control |
| 5 | --- | Not Used |
| 6 | --- | Not Used |
| 7 | GRY | Engine Oil Pressure (EOP) Sensor 5 Volt Reference |
| 8 | GRY | TPS Sensor 5 Volt Reference (w/o JL4 *) |
| 9 | -- | Not Used |
| 10 | --- | Not Used |
| 11 | LT BLU | Knock Sensor 2 Signal |
| 12 | YEL | CKP Sensor Signal |
| 13 | ORG/BLK | Requested Torque Signal (w/ JL4 *) |
| 14 | ORG/BLK | UART Serial Data (w/ JL4 *) |
| 15 | DK BLU/WHT | UART Serial Data (w/ JL4 *) |
| 16 | --- | Not Used |
| 17 | DK BLU | Transmission Fluid Pressure Switch Signal B |
| 18 | ORG | Transmission Fluid Pressure Switch Signal C (Late Production) |
| RED | Transmission Fluid Pressure Switch Signal C (Early Production) | |
| 19 | PNK | Ignition 1 Voltage (12 Volts) |
| 20 | RED/WHT | 12 Volts (Battery) - Late Production |
| ORG | 12 Volts (Battery) - Early Production | |
| 21 | PPL | CKP Sensor Low Reference (Ground) |
| 22 | --- | Not Used |
| 23 | TAN | Low Reference (Ground) -Fuel Tank Level Sender, Fuel Tank Pressure Sensor (Late Production) |
| BLK | Low Reference (Ground) -Fuel Tank Level Sender, Fuel Tank Pressure Sensor (Early Production) | |
| 24 | BLK/WHT | Chassis Ground |
| 25 | TAN | HO2S Low Signal Bank 2 Sensor 2 |
| 26 | TAN | HO2S Low Signal Bank 2 Sensor 1 |
| 27 | BLK/WHT | Chassis Ground |
| 28 | TAN/WHT | HO2S Low Signal Bank 1 Sensor 2 |
| 29 | TAN | HO2S Low Signal Bank 1 Sensor 1 |
| 30 | --- | Not Used |
| 31 | --- | Not Used |
| 32 | TAN/WHT | Transmission Range Switch Signal A (Late Production) |
| BLK/WHT | Transmission Range Switch Signal A (Early Production) | |
| 33 | PPL | TCC Brake Switch/Cruise Control Release Signal |
| 34 | WHT | Transmission Range Switch Signal P |
| 35 | --- | Not Used |
| 36 | TAN | Fuel Inj. #1 Control (Late Production) |
| BLK | Fuel Inj. #1 Control (Early Production) | |
| 37 | YEL/BLK | Fuel Inj. #6 Control |
| 38 | --- | Not Used |
| 39 | YEL/BLK | Starter Enable Relay Control |
| 40 | BLK/WHT | Chassis Ground |
* See this section: What Is JL4 And How Do I Find Out If My Van Has It?
NOTE: You can find the wire color legend here: PCM Connector Pinout Wire Color Legend
| C1 (Blue) Terminals 41 - 80 | ||
|---|---|---|
| Pin | Wire Color | Description |
| 41 | --- | Not Used |
| 42 | --- | Not Used |
| 43 | ORG/BLK | Fuel Inj. #7 Control (Late Production) |
| RED/BLK | Fuel Inj. #7 Control (Early Production) | |
| 44 | LT BLU/BLK | Fuel Inj. #4 Control |
| 45 | --- | Not Used |
| 46 | GRY | Fuel Tank Pressure Sensor 5 Volt Reference |
| 47 | --- | Not Used |
| 48 | GRY | MAP Sensor 5 Volt Reference |
| 49 | --- | Not Used |
| 50 | --- | Not Used |
| 51 | DK BLU | Knock Sensor 1 Signal |
| 52 | --- | Not Used |
| 53 | TAN | Transmission Fluid Temperature (TFT) Sensor Sensor Ground (Low Reference) - Late Production |
| BLK | Transmission Fluid Temperature (TFT) Sensor Sensor Ground (Low Reference) - Early Production | |
| 54 | ORG/BLK | MAP Sensor Ground (Low Reference) |
| 55 | --- | Not Used |
| 56 | --- | Not Used |
| 57 | RED/WHT | 12 Volts (Battery) - Late Production |
| ORG | 12 Volts (Battery) - Early Production | |
| 58 | DK GRN | Class 2 Serial Data |
| 59 | YEL | Class 2 Serial Data |
| 60 | TAN | TPS Sensor Ground (Low Reference) - Late Production (w/o JL4 *) |
| BLK | TPS Sensor Ground (Low Reference) - Early Production (w/o JL4 *) | |
| 61 | PNK/BLK | CMP Sensor Ground (Low Reference) |
| 62 | --- | Not Used |
| 63 | BLK | Engine Oil Pressure Sensor Ground (Low Reference) |
| 64 | BLK/WHT | Chassis Ground |
| 65 | PPL | HO2S High Signal - Bank 2 Sensor 2 |
| 66 | PPL | HO2S High Signal - Bank 2 Sensor 1 |
| 67 | BLK/WHT | Chassis Ground |
| 68 | PPL/WHT | HO2S High Signal - Bank 1 Sensor 2 |
| 69 | PPL/WHT | HO2S High Signal - Bank 1 Sensor 1 |
| 70 | BRN | Oil Level Switch Signal |
| 71 | --- | Not Used |
| 72 | YEL | Transmission Range Switch Signal B |
| 73 | BRN/WHT | CMP Sensor Signal |
| 74 | YEL | ECT Sensor Signal |
| 75 | PNK | Ignition Voltage - IGN0 Fuse |
| 76 | TAN/WHT | Fuel Inj. #5 Control (Late Production) |
| BLK/WHT | Fuel Inj. #5 Control (Early Production) | |
| 77 | DK BLU/WHT | Fuel Inj. #8 Control |
| 78 | --- | Not Used |
| 79 | WHT | 3-2 Shift Solenoid Valve Control (5.3L Only) |
| 80 | TAN | ECT Sensor Ground (Low Reference) - Late Production |
| BLK | ECT Sensor Ground (Low Reference) - Early Production | |
* See this section: What Is JL4 And How Do I Find Out If My Van Has It?
NOTE: You can find the wire color legend here: PCM Connector Pinout Wire Color Legend
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.
- You should never disconnect any of the PCM connectors without first disconnecting the battery negative (-) terminal.
- This is a FLASH unit and requires reprogramming if replaced with a new one or used one.
