Preliminary work: Diagnosis - Diagnostic Trouble Code (DTC) Memory 12

Preparation for Test: 1. Fuses OK. 2. Battery voltage >11 V. 3. Install model specific HHT module into HHT. 4. Connect Hand-Held Tester (HHT) ) according to connection diagram shown in section 0. 5. Connect socket box with test harness according to connection diagram (see 22, Figure 1 and 2). 6. Model 129: Connect impluse counter according to connection diagram (see section 0). Electrical wiring diagrams: Electrical Troubleshooting Manual, Model 129, Volume 2, group 80, Model 140, Volume 2, group 80, Model 202, Volume 2, group 80, Model 210, Volume 2, group 80.

Conventional tools, test equipment

Description	Brand, model, etc.
Multimeter 1)	Fluke models 23, 83, 85, 87, 88

1) Available through the MBUSA Standard Equipment Program.