Section 3 · Pages 31–148 (118 pages)

Computer Command Control (Scan Tool Diagnosis)

From the 1989 GMC Light Duty Truck Fuel, Emissions and Driveability Manual

The heart of the book: Computer Command Control with throttle body injection, diagnosed with a scan tool. It describes the ECM and its inputs (throttle position sensor for TBI 220 and TBI 700, vehicle speed and MAT sensors, park/neutral and power steering pressure switches, distributor reference and A/C signals), then gives the A-series diagnostic charts such as engine cranks but will not run, injector circuit and fuel pump relay circuit, trouble code charts from Code 13 (oxygen sensor) to Code 54 (fuel pump circuit), and on-vehicle service of harnesses and connectors.

Read this section free, starting at page 31

What this section covers

  • ECM inputs and outputs
  • Scan tool data
  • Chart A diagnostics (no start, injectors, fuel pump relay)
  • Trouble code charts
  • Wire harness and connector repair
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
Type
Fuel & Emissions, Supplement
Models
R/V, G, P, S/T, M, C/K 10–30
Publication
X-8936
Pages
274

What’s inside

Fuel and emissions manual

  1. 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
  2. 1General Informationpp. 7–24
  3. 2Driveability Symptomspp. 25–30
  4. 3Computer Command Control (Scan Tool Diagnosis)pp. 31–148
  5. 4Fuel Control System (TBI 220 and TBI 700)pp. 149–192
  6. 5Evaporative Emission Control System (EECS)pp. 193–198
  7. 6Ignition System and ESTpp. 199–206
  8. 7Electronic Spark Control (ESC)pp. 207–210
  9. 8Air Management Systempp. 211–220
  10. 9Exhaust Gas Recirculation (EGR)pp. 221–230
  11. 10Automatic and Manual Transmission Controlspp. 231–240
  12. 11Positive Crankcase Ventilation (PCV)pp. 241–244
  13. 12Thermostatic Air Cleaner (THERMAC)pp. 245–250
  14. 13Special Toolspp. 251–258
  15. 14Abbreviations and Glossarypp. 259–274

Other manuals for this vehicle