PCM Bench Harness Build

[MrBullSTR]

If anyone would like to share their experience with building one of these please by all means do.

I grabbed a set of PCM connectors and an OBDII port at the salvage yard and I am going to build a bench harness.

96 Grand Prix GTP-#16211539, with the 3.4L DOHC.

Connector one PCM C1 BLUE
PIN#19 Power Ignition (Pink) *Hot in RUN*
PIN#20 Battery (Orange) *Hot At All Times*
PIN#21 PCM Ground (Tan/White)
PIN#59 DLC Class 2 Data (Purple)
PIN#60 PCM Ground (Black/White)
PIN#68 Power Ignition (Pink) *Hot in RUN*

**May Not be Required**
Connector two PCM C2 CLEAR
PIN#21 PCM Ground (Black/White)
PIN#60 PCM Ground (Tan/White)

Two 12v switches w/LED, <=> 2Amp Fuse Holder <=> Connected to Bench Top Power Source @12V 1amp
Switch (LED) #1 <=> 2Amp Fuse <=> PIN#20 (Hot at all times)
<=> OBD2 Data Connector PIN#16
<=> (To switch #2)<=>
Switch (LED) #2 <=> PIN#19 (Hot in Run)
<=> PIN#68 (Hot in Run)

*All Grounds to ground of the 12v power supply.

OBDII Data Connector
PIN#2 <=> PIN#59 DLC Class 2 Data (Purple)
PIN#4 <=> Ground
PIN#5 <=> Ground
PIN#16 <=> 12V 2Amp Fuse <=> Switch #1

[NISANDA]

This is the Bench harness i use to read ALL 99 to 06 PCMs (Gen 3), 4Cil (ecotec Blue/clear), V6 (Blue/clear) and all V8 (Blue/Red, Blue/Green).

Connector one PCM C1 BLUE
PIN#19 Power Ignition *Hot in RUN*
PIN#20 Battery *Hot At All Times*
PIN#1 PCM Ground
PIN#58 DLC Class 2 Data
PIN#40 PCM Ground
PIN#75 Power Ignition *Hot in RUN*

OBDII Data Connector
PIN#2 <=> PIN#58 DLC Class 2 Data (Purple)
PIN#4 <=> Ground
PIN#5 <=> Ground
PIN#16 <=> 12V *Hot At All Times*

That's it, Maybe you pcm different? or where do you get the diagram?