2006 Cadillac STS VFACTORY OEM SERVICE PROCEDURE

Engine Control Module (ECM) C2

Fig 1: ECM C2 Connector
GM1650395Courtesy of GENERAL MOTORS CORP.
Engine Control Module Connector End Views

Connector Part Information 
  • OEM: 34566-0103
  • Service: 88988931
  • Description: 73-Way F (BK)
Terminal Part Information 
  • Pins: 73
  • Terminal/Tray: 7116-4152-02/9
  • Core/Insulation Crimp: 2/5
  • Release Tool/Test Probe: 12094430/J-35616-35 (VT)
  • Pins: 13, 28, 45, 65
  • Terminal/Tray: 33467-0003/23
  • Core/Insulation Crimp: H/H
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 11, 12
  • Terminal/Tray: 33467-0005/23
  • Core/Insulation Crimp: Pins 1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72 - J/J
  • Core/Insulation Crimp: Pins 11, 12 - K/K
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
Engine Control Module (ECM) C2

Pin Wire Color Circuit No. Function
1 PU 2121 IC 1 Control
2 TN/WH 3111 HO2S Low Reference (Bank 1 Sensor 1)
3 PU/WH 3110 HO2S Reference Voltage (Bank 1 Sensor 1)
4 PU 3120 HO2S High Signal (Bank 1 Sensor 2)
5 TN/WH 3121 HO2S Low Signal (Bank 1 Sensor 2)
6 L-BU 1876 Knock Sensor 2 Signal
7 GY 2303 Low Reference
8 D-BU 496 Knock Sensor (1) Signal
9 GY 1716 Low Reference
10 - - Not Used
11 YE 581 TAC Motor Control - 1
12 BN 582 TAC Motor Control - 2
13 PK/BK 5290 Ignition 1 Voltage
14 PK/BK 6395 Camshaft Position (CMP) Actuator Solenoid - Intake Bank 1 Control
15 TN/BK 6397 Camshaft Position (CMP) Actuator Solenoid - Intake Bank 2 Control
16 D-BU/WH 878 Fuel Injector 8 Control
17 OG/WH 2122 IC 2 Control
18 L-BU/WH 2126 IC 6 Control
19 BN/WH 2130 Low Reference
20 PU 6267 Low Reference
21 TN 6268 Low Reference
22 WH 6269 Low Reference
23 BN 6266 Low Reference
24 BK 2755 Low Reference
25 D-GN 7125 Super Charger Inlet Air Pressure Sensor Return
26 - - Not Used
27 GY/BK 6272 Low Reference
28 PK/BK 5290 Ignition 1 Voltage
29 TN 2752 Low Reference
30 BN/WH 6754 Low Reference
31 D-BU/WH 6756 Low Reference
32 PK/BK 1746 Fuel Injector 3 Control
33 OG 2127 IC 7 Control
34 D-GN 2125 IC 5 Control
35 BN 2129 Low Reference
36 D-GN 6457 Camshaft Position (CMP) Sensor - Exhaust Bank 1 Signal
37 OG 6260 Camshaft Position (CMP) Sensor - Intake Bank 2 Signal
38 PK 6261 Camshaft Position (CMP) Sensor - Exhaust Bank 2 Signal
39 D-GN 6259 Camshaft Position (CMP) Sensor - Intake Bank 1 Signal
40 GY 2705 5-Volt Reference
41 YE/BK 7124 5-Volt Reference
42 TN 2760 Low Reference
43 PU/WH 6270 5-Volt Reference
44 GY 2701 5-Volt Reference
45 BN 6273 Oil Temperature Sensor Low Reference
46 BN 6753 Low Reference
47 D-BU 6755 Low Reference
48 L-GN/BK 1745 Fuel Injector 2 Control
49 TN/WH 845 Fuel Injector 5 Control
50 WH/BK 6396 Camshaft Position (CMP) Actuator Solenoid - Exhaust Bank 1 Control
51 GY/BK 6394 Camshaft Position (CMP) Actuator Solenoid - Exhaust Bank 2 Control
52 L-BU/BK 844 Fuel Injector 4 Control
53 L-BU 2123 IC 3 Control
54 D-GN/WH 2124 IC 4 Control
55 PU/WH 2128 IC 5 Control
56 D-GN/WH 6264 5-Volt Reference
57 OG/BK 6263 5-Volt Reference
58 PK/BK 6262 5-Volt Reference
59 D-BU/WH 6265 5-Volt Reference
60 TN/WH 331 Oil Pressure Sensor Signal
61 - - Not Used
62 TN 472 IAT Sensor Signal
63 WH/BK 6271 CKP Sensor Signal
64 D-GN 485 TP Sensor 1 Signal
65 D-GN/WH 357 TCC Release Switch Signal
66 PU 486 TP Sensor 2 Signal
67 YE 492 MAF Sensor Signal
68 GY/WH 3113 HO2S Heater Low Control (Bank 1 Sensor 1)
69 GY/WH 3122 HO2S Heater Low Control (Bank 2 Sensor 1)
70 YE/BK 846 Fuel Injector 6 Control
71 OG/BK 877 Fuel Injector 7 Control
72 TN 1744 Fuel Injector 1Control
73 BK/WH 1551 Ground
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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.