2004 Cadillac CTS VFACTORY OEM SERVICE PROCEDURE

Powertrain Control Module (PCM) Connector End Views

Powertrain Control Module (PCM) C1

GM655733Courtesy of GENERAL MOTORS CORP.
Connector Part Information
  • 12191489
  • 80-Way F Micro-Pack 100W Sealed (BU)
Pin Wire Color Circuit No. Function
1 BK 750 Ground
2 L-GN 1867 12-Volt Reference
3 PK/BK 1746 Fuel Injector 3 Control
4 L-GN/BK 1745 Fuel Injector 2 Control
5-6 - - Not Used
7 GY 2705 5-Volt Reference A
8-10 - - Not Used
11 L-BU 1876 Knock Sensor 2 Signal
12 D-BU/WH 1869 CKP Sensor Signal
13 OG/BK 463 Requested Torque Signal
14 TN 800 UART Serial Data
15 D-BU/WH 774 UART Serial Data
16-18 - - Not Used
19 PK 239 Ignition 1 Voltage
20 RD/WH 1440 Battery Positive Voltage
21 YE/BK 1868 Low Reference
22 - - Not Used
23 TN 452 Low Reference
24 BK/WH 1451 Ground
25 TN 1671 HO2S Low Signal - Bank 2 Sensor 2
26 TN 1667 HO2S Low Signal - Bank 2 Sensor 1
27 BK/WH 1551 Ground
28 TN/WH 1669 HO2S Low Signal - Bank 1 Sensor 2
29 TN 1664 HO2S Low Signal - Bank 1 Sensor 1
30-34 - - Not Used
35 BN/WH 379 CPP Switch Signal
36 TN 1744 Fuel Injector 1 Control
37 YE/BK 846 Fuel Injector 6 Control
38 - - Not Used
39 YE 447 Starter Relay Coil Control
40 BK 750 Ground
41 - - Not Used
42 D-GN 335 Low Speed Cooling Fan Relay Control
43 OG/BK 877 Fuel Injector 7 Control
44 L-BU/BK 844 Fuel Injector 4 Control
45 GY 2700 5-Volt Reference B
46 GY 596 5-Volt Reference B
47 - - Not Used
48 GY 2704 5-Volt Reference A
49-50 - - Not Used
51 D-BU 496 Knock Sensor 1 Signal
52 - - Not Used
53 OG/BK 1057 Low Reference
54 OG/BK 469 Low Reference
55-56 - - Not Used
57 RD/WH 1440 Battery Positive Voltage
58 PU 1807 Class 2 Serial Data
59 PU 1807 Class 2 Serial Data
60 - - Not Used
61 PK/BK 632 Low Reference
62 GY 847 Extended Travel Brake Switch Signal
63 BK 2755 Low Reference
64 BK/WH 1451 Ground
65 PU 1670 HO2S High Signal - Bank 2 Sensor 2
66 PU 1666 HO2S High Signal - Bank 2 Sensor 1
67 BK/WH 1551 Ground
68 PU/WH 1668 HO2S High Signal - Bank 1 Sensor 2
69 PU/WH 1665 HO2S High Signal - Bank 1 Sensor 1
70 BN 1174 Oil Level Switch Signal
71-72 - - Not Used
73 BN/WH 633 CMP Sensor Signal
74 YE 410 ECT Sensor Signal
75 - - Not Used
76 TN/WH 845 Fuel Injector 5 Control
77 D-BU/WH 878 Fuel Injector 8 Control
78 - - Not Used
79 GY 587 Skip/Shift Solenoid Control
80 TN 2761 Low Reference
Powertrain Control Module (PCM) C2

GM684875Courtesy of GENERAL MOTORS CORP.
Connector Part Information
  • 12191488
  • 80-Way F Micro-Pack 100W Sealed (GN)
Pin Wire Color Circuit No. Function
1 BK 750 Ground
2-4 - - Not Used
5 TN/BK 464 Delivered Torque Signal
6-8 - - Not Used
9 D-GN/WH 465 Fuel Pump Relay Control
10 WH 121 Engine Speed Signal
11-13 - - Not Used
14 OG/BK 380 A/C Refrigerant Pressure Sensor Signal
15 OG 225 Generator Turn On Signal
16-17 - - Not Used
18 PU/WH 1035 Starter Relay Coil Supply Voltage
19 - - Not Used
20 L-GN/BK 822 VSS Low Signal
21 PU/WH 821 VSS High Signal
22-24 - - Not Used
25 TN 472 IAT Sensor Signal
26 PU 2121 IC 1 Control
27 OG 2127 IC 7 Control
28 L-BU/WH 2126 IC 6 Control
29 D-GN/WH 2124 IC 4 Control
30 - - Not Used
31 YE 492 MAF Sensor Signal
32 L-GN 432 MAP Sensor Signal
33 D-BU 473 High Speed Cooling Fan Relay Control
34 D-GN/WH 428 EVAP Canister Purge Solenoid Control
35-38 - - Not Used
39 OG 631 12-Volt Reference
40 BK 750 Ground
41-42 - - Not Used
43 D-GN/WH 459 A/C Compressor Clutch Relay Control
44 L-GN 1652 Reverse Lockout Solenoid Control
45 WH 1310 EVAP Canister Vent Solenoid Control
46 BN/WH 419 MIL Control
47 WH 375 Skip Shift Indicator Control
48-49 - - Not Used
50 BN 818 Vehicle Speed Signal
51 YE/BK 1227 TFT Sensor Signal
52 BN 2391 HO2S Heater Low Control - Bank 1 Sensor 2
53 OG/WH 3223 HO2S Heater Low Control - Bank 2 Sensor 2
54 D-BU 1936 Fuel Level Sensor Signal - Primary
55-56 - - Not Used
57 TN 552 Low Reference
58 TN/WH 331 Oil Pressure Sensor Signal
59 YE 5 Crank Voltage
60 BN 2129 Low Reference
61 BN/WH 2130 Low Reference
62-63 - - Not Used
64 D-GN 890 Fuel Tank Pressure Sensor Signal
65 BN 5069 MAIN Relay Control
66 PU/WH 2128 IC 8 Control
67 OG/WH 2122 IC 2 Control
68 D-GN 2125 IC 5 Control
69 L-BU 2123 IC 3 Control
70-71 - - Not Used
72 GY/WH 3113 HO2S Heater Low Control - Bank 1 Sensor 1
73 L-BU 1937 Fuel Level Sensor Signal - Secondary
74 L-GN 3212 HO2S Heater Low Control - Bank 2 Sensor 1
75 GY 23 Generator Field Duty Cycle Signal
76-79 - - Not Used
80 TN 5514 Low Reference
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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