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HOMESERVICE MANUALSCHEVROLET2008CHEVY EXPRESS G2500, VAN CARGO, 6.6 6REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 2700 (WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - 5 OF 5)TRANSMISSION CONTROL MODULE
2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6

Transmission Control Module

2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Transmission Control Module
WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Transmission Control Module (TCM) Connector End View
GM821223Courtesy of GENERAL MOTORS CORP.
Transmission Control Module

Pin Wire Circuit Function
1 0.35 YE 400 OSS High Signal
2 0.35 PU 401 OSS Low Signal
3 0.35 OG/BK 1228 PC Solenoid Valve High Control
4 0.35 BN 418 TCC Solenoid Valve Control
5 0.35 YE/BK 5728 ECM/TCM Serial Data Wake Up
6 0.35 BK/WH 751 Ground (5L40/6L50)
1 BK/WH 1551 Ground (5L50)
7 - - Not Used
8 0.35 OG 1525 Solenoid Supply Voltage
9 0.35 PK 239 Ignition 1 Voltage
10 0.35 OG/BK 1230 ISS High Signal
11 0.35 D-BU/WH 1231 ISS Low Signal
12-13 - - Not Used
14 0.35 PU 5526 Tap Up/Tap Down Signal
15 0.35 YE/BK 1227 TFT Sensor Signal
16-17 - - Not Used
18 0.35 YE/BK 1223 2-3 Shift Solenoid Valve Control
19 0.35 PU 898 4-5 Shift Solenoid Valve Control
20 0.35 TN/BK 2500 High Speed GMLAN Serial Data Bus+
21 0.35 TN 2501 High Speed GMLAN Serial Data Bus-
22-23 - - Not Used
24 0.35 YE 772 Transmission Range Signal B
25 0.35 GY 773 Transmission Range Signal C
26 0.35 TN 2762 Low Reference
27 0.35 RD/WH 1440 Battery Positive Voltage
28 - - Not Used
29 0.35 L-BU/WH 1229 PC Solenoid Valve Low Control
30 0.35 L-GN 1222 1-2 Shift Solenoid Valve Control
31 - - Not Used
32 0.35 TN/BK 2500 High Speed GMLAN Serial Data Bus+
33 0.35 TN 2501 High Speed GMLAN Serial Data Bus-
34-35 - - Not Used
36 0.35 TN/WH 771 Transmission Range Signal A
37 0.35 WH 776 Transmission Range Signal P
38 0.35 WH 17 TCC Brake Switch Signal
39-42 - - Not Used
Connector Part Information 
  • OEM: 88956573
  • Service: See Catalog
  • Description: 42-Way F Module 1 Socket Housing (BK)
Terminal Part Information 
  • Terminal/Tray: See Terminal Repair Kit
  • Core/Insulation Crimp: See Terminal Repair Kit
  • Release Tool/Test Probe: See Terminal Repair Kit
RENDER: 1.0x

NO RELATED

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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.