1. Ignition: OFF 2. Disconnect ASR/SPS or ETS/SPS control module (N47-1 or N47-2). 3. Connect socket box with test cable as per connection diagram (Figure 1). Note: The measured voltages will be slightly lower in diesel models during preglow. Electrical Wiring Diagrams: Electrical Troubleshooting Manual, Model 129, Electrical Troubleshooting Manual, Model 140. When exchanging an ETS/SPS control module, the replacement module must have the code data entered via the HHT. Follow instructions on HHT display.

Conventional tools, test Equipment

Description	Brand, model, etc.
Digital multimeter 1)	Fluke models 23, 83, 85, 87

1) Available through the MBUSA Standard Equipment Program.