2005 Chevrolet Avalanche 2500FACTORY OEM SERVICE PROCEDURE

Powertrain Control Module (PCM) Connectors

Powertrain Control Module (PCM) C1 Connector End View

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/WH 451 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
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 OG/BK 1061 UART Serial Data
15 D-BU/
WH		 774 UART Serial Data
16 - - Not Used
17 D-BU 1225 Transmission Fluid Pressure Switch Signal B
18 RD 1226 Transmission Fluid Pressure Switch Signal C
19 PK 439 Ignition 1 Voltage
20 OG 440 Battery Positive Voltage
21 YE/BK 1868 Low Reference
22 - - Not Used
23 BK 470 Low Reference
24 BK/WH 451 Ground
25 TN 1671 HO2S Low Signal Bank 2 Sensor 2
26 TN 1667 HO2S Low Signal Bank 2 Sensor 1
27 BK/WH 451 Ground
28 TN/WH 1669 HO2S Low Signal Bank 1 Sensor 2
29 TN 1664 HO2S Low Signal Bank 1 Sensor 1
30 L-GN 1478 Coolant Level Switch Signal
31 - - Not Used
32 BK/WH 771 Transmission Range Switch Signal A
33 PU 420 TCC Brake Switch/Cruise Control Release Signal
34 WH 776 Transmission Range Switch Signal P
35 - - Not Used
36 BK 1744 Fuel Injector 1 Control
37 YE/BK 846 Fuel Injector 6 Control
38 PK/WH 1101 Damping Lift/Dive Signal
39 YE/BK 625 Starter Enable Relay Control
40 BK/WH 451 Ground
41-42 - - Not Used
43 RD/BK 877 Fuel Injector 7 Control
44 L-BU/BK 844 Fuel Injector 4 Control
45 GY 2700 5-Volt Reference
46 GY 474 5-Volt Reference
47 - - Not Used
48 GY 597 5-Volt Reference
49-50 - - Not Used
51 D-BU 496 Knock Sensor 1 Signal
52 - - Not Used
53 GY 720 Low Reference
54 OG/BK 469 Low Reference
55 - - Not Used
56 - - Not Used
57 OG 440 Battery Positive Voltage
58 D-GN 1049 Class 2 Serial Data
59-60 - - Not Used
61 PK/BK 632 Low Reference
62 - - Not Used
63 BK 2755 Low Reference
64 BK/WH 451 Ground
65 PU 1670 HO2S High Signal Bank 2 Sensor 2
66 PU 1666 HO2S High Signal Bank 2 Sensor 1
67 BK/WH 451 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 - - Not Used
72 YE 772 Transmission Range Switch Signal B
73 BN/WH 633 CMP Sensor Signal
74 YE 410 ECT Sensor Signal
75 PK 1020 Ignition 0 Voltage
76 BK/WH 845 Fuel Injector 5 Control
77 D-BU/
WH		 878 Fuel Injector 8 Control
78-79 - - Not Used
80 BK 720 Low Reference
Powertrain Control Module (PCM) C2 Connector End View

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/WH 451 Ground
2 BN 418 TCC PWM Solenoid Valve Control
3 TN 1465 Fuel Pump Relay Control - Secondary
4 - - Not Used
5 TN/BK 464 Delivered Torque Signal
6 RD/BK 1228 PC Solenoid Valve High Control
7 - - Not Used
8 L-BU/WH 1229 PC Solenoid Valve Low Control
9 D-GN/
WH		 465 Fuel Pump Relay Control
10 WH 121 Engine Speed Signal
11-13 - - Not Used
14 RD/BK 380 A/C Refrigerant Pressure Sensor Signal
15 BN 25 Charge Indicator Control
16 GY/BK 1694 4WD Low Signal (NP8/NR4)
17-18 - - Not Used
19 - - Not Used
20 L-GN/BK 822 VSS Low Signal
21 PU/WH 821 VSS High Signal
22 RD/BK 1230 AT ISS High Signal
23 D-BU/WH 1231 AT ISS Low Signal
24 - - Not Used
25 TN 472 IAT Sensor Signal
26 PU 2121 IC 1 Control
27 RD 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 - - Not Used
34 D-GN/
WH		 428 EVAP Canister Purge Solenoid Control
35-38 - - Not Used
39 RD 631 12-Volt Reference
40 BK/WH 451 Ground
41-42 - - Not Used
43 D-GN/
WH		 459 A/C Compressor Clutch Relay Control
44 - - Not Used
45 WH 1310 EVAP Canister Vent Solenoid Control
46 BN/WH 419 MIL Control
47 YE/BK 1223 2-3 Shift Solenoid Valve Control
48 L-GN 1222 1-2 Shift Solenoid Valve Control
49 YE/BK 1827 Vehicle Speed Signal
50 D-GN/
WH		 817 Vehicle Speed Signal
51 YE/BK 1227 TFT Sensor Signal
52 BN 2391 HO2S Heater Low Control Bank 1 Sensor 2
53 RD/WH 3223 HO2S Heater Low Control Bank 2 Sensor 2
54 PU 1589 Fuel Level Sensor Signal
55-56 - - Not Used
57 BK 552 Low Reference
58 TN/WH 332 Oil Pressure Sensor Signal
59 PU 806 Crank Voltage
60 BN 2129 Low Reference
61 BN/WH 2130 Low Reference
62 GY 773 Transmission Range Switch Signal C
63 PK 1224 Transmission Fluid Pressure Switch Signal A
64 D-GN 890 Fuel Tank Pressure Sensor Signal
65 - - Not Used
66 PU/WH 2128 IC 8 Control
67 RD/WH 2122 IC 2 Control
68 D-GN 2125 IC 5 Control
69 L-BU 2123 IC 3 Control
70-71 - - Not Used
72 BK/WH 3113 HO2S Heater Low Control Bank 1 Sensor 2
73 D-BU 1936 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 BK 2751 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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