LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Oldsmobile >> 1986 >> Toronado >> Repair and Diagnosis >> Engine Performance >> Ignition System - C3I >> Testing >> Electronic Spark Control System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Electronic Spark Control System

  1. Connect tachometer to terminal "D" of ignition module. Place transmission in "P" or "N". Start engine. Run at approximately 1500 RPM. Tap engine block in area of knock sensor and check for RPM drop.
  2. If RPM drops, system is okay. If no RPM drop, unplug the ESC module and check for RPM drop. If there is no RPM drop, go to step 6).
  3. If RPM drops, run engine at 2000 RPM and check voltage between pins "E" and "D" with digital voltmeter. There should be over 80 millivolts (.080 volts) at 2000 RPM.
  4. If voltage is correct, check for faulty ESC connection or ESC module. If voltage is not correct, check for open in ground circuit. Ground is Blk/Wht wire at terminal "D" of ESC module.
  5. If ground circuit is okay, check for faulty connection from knock sensor to module. If circuit is okay, replace knock sensor.
  6. If there was no RPM drop when ESC module was disconnected in step 2), check engine light. If light is off, turn engine off and turn ignition on. Check if there is 2 volts present at ESC harness terminal "C".
  7. If there is less than 2 volts, replace ECM. If over 2 volts, correct short on Yellow wire from ESC terminal "C" to ECM terminal "B7".
  8. If engine light was on in step 6), turn ignition off. Disconnect ESC module connector. Remove knock sensor wire (Dark Blue) from ESC module. Install a jumper wire from terminal E on ESC module to sensor wire. Start engine.
  9. With engine running at 1800 RPM, disconnect jumper wire. Check RPM drop. If there was no RPM drop, repair or replace ESC connector. If connector is okay, replace ESC module. If there was a RPM change, check knock sensor wire for short. If wire is okay, replace knock sensor.
scientia non olet · About LEMON Manuals