Transmission Control Module (TCM) (4.3L/4.8L/5.3L/6.0L)

2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Transmission Control Module (TCM) (4.3L/4.8L/5.3L/6.0L)
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2009 GMC Savana Special, 2009 GMC Savana Camper Special, 2009 GMC Savana, 2009 Chevrolet RV Cutaway, and 2009 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Transmission Control Module (TCM) (4.3L/4.8L/5.3L/6.0L) - Connector End View
GM1544228Courtesy of GENERAL MOTORS CORP.
Connector Part Information 
  • OEM: 15463921
  • Service: 88987979
  • Description: 49-Way F GT 280 Micro-Pack 64 Sealed (BK)
Terminal Part Information 
  • Pins: 1-3, 5-7, 11, 14-17, 19, 20, 23-26, 29, 30-33, 35, 37-42, 44-46
  • Terminal/Tray: 15359541/4
  • Core/Insulation Crimp: M/M
  • Release Tool/Test Probe: 15381651-2/J-35616-64B (L-BU)
  • Pins: 49
  • Terminal/Tray: 15392777/23
  • Core/Insulation Crimp: See Terminal Repair Kit
  • Release Tool/Test Probe: J-38125-553/J-35616-4A (PU)
Transmission Control Module (TCM) (4.3L/4.8L/5.3L/6.0L)

Pin Wire Circuit Function
1 0.5 BN 418 Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid Valve Control
2 0.5 L-GN 1222 Shift Solenoid A Valve Control
3 0.5 OG/BK 1230 Automatic Transmission Input Speed Sensor (AT ISS) High Signal
4 - - Not Used
5 0.5 OG/BK 6399 Replicated TOS Signal
6 0.5 TN 2501 High Speed GMLAN Serial Data Bus (-)
7 0.5 TN/BK 2500 High Speed GMLAN Serial Data Bus (+)
8-10 - - Not Used
11 0.5 D-BU 5985 Accessory Wakeup Serial Data
12-14 - - Not Used
15 0.5 TN 2501 High Speed GMLAN Serial Data Bus (-)
16 0.5 L-GN/BK 822 Vehicle Speed Sensor (VSS) Low Signal
17 0.35 L-BU/WH 1229 PC Solenoid Valve Low Control (Sol. A)
18 - - Not Used
19 0.5 TN/BK 2500 High Speed GMLAN Serial Data Bus (+)
20 0.5 YE/BK 1223 Shift Solenoid B Valve Control
21-22 - - Not Used
23 0.35 GY 773 Transmission Range Switch Signal C
24 0.35 PK 1224 Transmission Fluid Pressure Switch Signal A (4L80)
25 0.5 TN/BK 422 Torque Converter Clutch (TCC) Solenoid Valve Control (4L60)
26 0.5 D-BU/WH 1231 Automatic Transmission Input Speed Sensor (AT ISS) Low Signal (4L80)
27-28 - - Not Used
29 0.35 TN/WH 771 Transmission Range Switch Signal A
30 0.35 TN 452 Low Reference
31 0.5 PK 2139 Ignition Voltage
32 0.35 RD/WH 1840 Battery Positive Voltage
33 0.35 OG 1226 Transmission Fluid Pressure Switch Signal C (4L80)
34 - - Not Used
35 0.35 YE/BK 1227 Transmission Fluid Temperature (TFT) Sensor Signal
36 - - Not Used
37 0.5 TN 2501 High Speed GMLAN Serial Data Bus (-)
38 0.5 TN/BK 2500 High Speed GMLAN Serial Data Bus (+)
39 0.35 WH 776 Transmission Range Switch Signal P
40 0.35 OG/BK 1228 PC Solenoid Valve High Control (Sol. A)
41 0.5 PU/WH 821 Vehicle Speed Sensor (VSS) High Signal
42 0.5 L-BU/WH 6311 Torque Converter Clutch (TCC) Brake Signal
43 - - Not Used
44 0.35 D-BU 1225 Transmission Fluid Pressure Switch Signal B (4L80)
45 0.35 D-BU/WH 1231 Low Reference (4L60)
46 0.35 YE 772 Transmission Range Switch Signal B
47-48 - - Not Used
49 2 BK/WH 1551 Ground
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.