PCM Connector: Blue (C1) 1996-1997

1996-1997 Blue PCM Connector Pinout

The 1996-97 PCM (Powertrain Control Module = Fuel Injection Computer) on your 4.3L, 5.0L or 5.7L Engine has a total of 4 connectors.

NOTE: For other PCM pin-out charts, take a look at the following:

  1. 1993 PCM Pin Out Chart (GM 4.3L, 5.0L, 5.7L GAS w/ 4L60-E).
  2. 1994 PCM Pin Out Chart (GM 4.3L, 5.0L, 5.7L GAS with A/T).
  3. 1995 PCM Pin Out Chart (GM 4.3L, 5.0L, 5.7L GAS with A/T).
  4. 1998-99 PCM Connector Pin Out Charts (GM 4.3L, 5.0L, 5.7L).

Each connector can be identified as:

  1. C1 Blue (32 Pin Connector).
  2. C2 Red (32 Pin Connector).
  3. C3 Clear -or Grey- (32 Pin Connector).
  4. C4 Black (24 Pin Connector).

Contents of this tutorial:

  1. C1 Blue.
  2. C2 Red.
  3. C3 Clear -or Grey-.
  4. C4 Black.

You'll notice in the chart below (and in the next page) that I'm using the following symbols: <->. This means that the Connector Pin # will have one of two different wires DEPENDING on whether your vehicle is equipped with a 4.3L, 5.0L, 5.7L, etc.

C1 (Blue) PCM 32 Pin Connector
Pin Wire Color Description
1 --- Empty
2 --- Empty
3 Brown w/ White stripe 1X CMP Signal
4 Pink Ignition Feed
5 <-> Yellow w/ Black stripe Injector #6 Control (4.3L only)
5 <-> Dark Blue w/ White stripe Injector #8 (except 4.3L)
6 --- Empty
7 Tan H02S Low Bank 2 Sensor 1
8 Pink w/ Black stripe CMP Sensor Low
9 --- Empty
10 Tan w/ Black stripe TCC Solenoid Control (4L60-E only)
11 --- Empty
12 Dark Green w/ White stripe EVAP Purge Solenoid Control
13 White 3-2 Control Solenoid (Automatic Transmission only)
14 Brown AIR Relay Control (7.4L California)
15 White VSS Output Signal (ABS)
16 --- Empty
17 --- Empty
18 Gray EGR Control
19 Purple w/ White stripe H02S High Bank 1 Sensor 1
20 Purple H02S High Bank 1 Sensor 2
21 Purple H02S High Bank 2 Sensor 1
22 <-> Purple w/ White stripe H02S Bank 1 Sensor 3 (4.3L and 5.0L only)
22 <-> Purple w/ White stripe H02S Bank 2 Sensor 2 (5.7L and 7.4L only)
23 --- Empty
24 Tan H02S Low Bank 1 Sensor 2
25 <-> Tan w/ White stripe HO2S Low Bank 2 Sensor 2 (5.7L and 7.4L only)
25 <-> Tan w/ White stripe HO2S Low Bank 1 Sensor 1
26 <-> Tan w/ White stripe HO2S Low Bank 1 Sensor 3 (4.3L and 5.0L only)
26 <-> Tan w/ White stripe HO2S Low Bank 2 Sensor 2 (5.7L and 7.4L only)
27 --- Empty
28 Purple Crank (CKP) Sensor Low
29 Light Green w/ Black stripe VSS Low
30 Purple w/ White stripe VSS Signal
31 <-> Yellow 3X Crank (CKP) Signal (4.3L only)
31 <-> Yellow 4X Crank (CKP) Signal (except 4.3L)
32 --- Empty

Safety Precautions

Here are some very important safety precautions when testing the wires coming out of the PCM connectors.

  1. 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.
  2. Never probe the front of the Connector.
    1. You should use a Wire Piercing Probe and probe the wire a few inches away from the connector.
      1. To see what this tool looks like: Wire Piercing Probe.
    2. You should use a Back Probe.
  3. You should never disconnect any of the PCM connectors without first disconnecting the battery negative terminal.
  4. This is a FLASH unit and requires reprogramming if replaced with a new one or used one.


I've made every effort to double and triple check the above info (and in the next couple of pages) and I've used the best sources to compile it but nothing in life is perfect. I don't have a staff of proof readers or editors, I'm just a little guy typing this stuff up in my spare time to help and give back to the Do-It-Yourself community. So without further ado, here's my disclaimer:

© copyright Abraham Torres-Arredondo: This information is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

If you do spot errors, please let me know. You can use the contact form at the end of the article.

PCM Connector Pinouts