2007 Chevrolet HHR LS, AutomaticFACTORY OEM SERVICE PROCEDURE

Engine Control Module (ECM) Connector End View C1

Fig 1: Connector End View
GM1590592Courtesy of GENERAL MOTORS CORP.
Connector Part Information

Connector Part Information 
  • OEM: 34566-8203
  • Service: 88988931
  • Description: 73-Way F MX 123 Series (BK)
Terminal Part Information 
  • Pins: 73
  • Terminal/Tray: 7116-4151-02/9
  • Core/Insulation Crimp: E/1
  • Release Tool/Test Probe: 12094430/J-35616-4A (PU)
  • Pins: 1, 3-6, 13, 18, 21, 24, 25, 27, 30, 31, 34, 36, 37, 39, 41-44, 47, 54-56, 58, 66, 67
  • Terminal/Tray: 33467-0003/23
  • Core/Insulation Crimp: H/H
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 19, 20, 70
  • Terminal/Tray: 33467-0005/23
  • Core/Insulation Crimp: J/J
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
Connector Terminal Identification

Pin Wire Color Circuit No. Function
1 D-BU 1161 APP Sensor 1 Signal
2 - - Not Used
3 BN 4 Accessory Voltage
4 PU 420 TCC Brake Switch/Cruise Control Release Signal
5 D-GN 335 Low Speed Cooling Fan Relay Control
6 L-GN/WH 465 Fuel Pump Relay Control (- Primary)
7-12 - - Not Used
13 BN 5069 Powertrain Relay Control
14-17 - - Not Used
18 L-BU 1162 APP Sensor 2 Signal
19 PK/BK 1039 Ignition 1 Voltage
20 RD/WH 840 Battery Positive Voltage
21 PU 1272 Low Reference
22-23 - - Not Used
24 TN 2759 Low Reference
25 OG/BK 380 A/C Refrigerant Pressure Sensor Signal
26 - - Not Used
27 BN/WH 419 MIL Control
28-29 - - Not Used
30 D-GN/WH 459 A/C Compressor Clutch Relay Control
31 YE 447 Starter Relay Coil Control
32-33 - - Not Used
34 PU/WH 6356 VSS Signal Low
35 - - Not Used
36 BN/WH 379 Cruise Control Clutch Pedal Position Switch Signal (M86)
37 YE 492 Mass Air Flow Sensor Signal
38 - - Not Used
39 PU 1589 Fuel Level Sensor Signal (+ Primary)
40 - - Not Used
41 BN 1271 Low Reference
42 D-GN 890 Fuel Tank Pressure Sensor Signal
43 TN/BK 2500 High Speed GMLAN Serial Data (+) (1)
44 TN 2501 High Speed GMLAN Serial Data (-) (1)
45-46 - - Not Used
47 WH/BK 1164 5-Volt Reference
48-53 - - Not Used
54 BN/WH 6354 VSS Signal High
55 L-BU 20 Stop Lamp Supply Voltage
56 D-GN 1433 PNP/Clutch Start Switch Signal (M86)
57 - - Not Used
58 TN 472 Intake Air Temperature Sensor Signal
59-65 - - Not Used
66 GY 2709 5-Volt Reference
67 TN 1274 5-Volt Reference
68-69 - - Not Used
70 WH 1310 EVAP Canister Vent Solenoid Control
71-72 - - Not Used
73 PK/BK 5290 Ignition 1 Voltage
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.