Section 6 · Pages 199–206 (8 pages)
Ignition System and EST
From the 1989 GMC Light Duty Truck Fuel, Emissions and Driveability Manual
The ignition system with Electronic Spark Timing: operation of the EST circuits, Hall effect switch and module, Code 42 diagnosis, the ignition system check, EST performance checks for the 2.5L and other engines, setting timing and on-vehicle service of the pick-up coil, module and distributor parts.
Read this section free, starting at page 199What this section covers
- EST operation
- Code 42 diagnosis
- Ignition system check
- EST performance check
- Setting timing
- Pick-up coil and module service
- Year
- 1989
- Make
- GMC
- Vehicle
- C/K Trucks, G Vans, Light Duty Trucks, M Vans (Astro/Safari), P Forward Control, R/V Trucks, S/T Trucks, Trucks
- Models
- R/V, G, P, S/T, M, C/K 10–30
- Publication
- X-8936
- Pages
- 274
What’s inside
Fuel and emissions manual
- Foreword and ContentsTitle page, foreword naming the shop manuals this book supplements, safety cautions on fasteners and service, and the table of contents.pp. 1–6
- 1General Informationpp. 7–24
- 2Driveability Symptomspp. 25–30
- 3Computer Command Control (Scan Tool Diagnosis)pp. 31–148
- 4Fuel Control System (TBI 220 and TBI 700)pp. 149–192
- 5Evaporative Emission Control System (EECS)pp. 193–198
- 6Ignition System and ESTpp. 199–206
- 7Electronic Spark Control (ESC)pp. 207–210
- 8Air Management Systempp. 211–220
- 9Exhaust Gas Recirculation (EGR)pp. 221–230
- 10Automatic and Manual Transmission Controlspp. 231–240
- 11Positive Crankcase Ventilation (PCV)pp. 241–244
- 12Thermostatic Air Cleaner (THERMAC)pp. 245–250
- 13Special Toolspp. 251–258
- 14Abbreviations and Glossarypp. 259–274







