LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2002 >> SL600 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics With Codes >> Diagnostic Tests >> DTC P0304: Misfire Cylinder 4 Or Misfire Cylinder 4 Damaging To TWC >> Testing Procedure (Ignition Coil T1/4)

Testing Procedure (Ignition Coil T1/4)

NOTE: Ignition coil (T1/4) is located on right cylinder bank. For ME-SFI control module location and identification, see ME-SFI CONTROL MODULE CONNECTOR IDENTIFICATION  .
  1. Primary Voltage, Ignition Coil (T1/4) -  Connect oscilloscope between right cylinder bank ME-SFI control module connector 2 terminal No. 115 (socket box terminal No. 115) and right cylinder bank ME-SFI control module connector 1 terminal No. 25 (socket box terminal No. 25). Observe oscilloscope while operating starter. Voltage should be 200-350 volts. If voltage is within specification, go to Testing Procedure (Ignition Coil Ignition Voltage T1/1 To T1/12)  . If voltage is not within specification, go to next step.
  2. Primary Winding Of Ignition Coil (T1/4) -  Turn ignition off. Connect DVOM between right cylinder bank ME-SFI control module connector 2 terminals No. 115 and 85 (socket box terminals No. 115 and 85). Resistance should be 0.9-1.4 ohms (resistance value of both T1/4 and T1/3 primary circuits). Resistance of primary winding of one ignition coil individually is 0.5-0.7 ohms at 68°F (20°C). If resistance is within specification, test is complete. If resistance is not within specification, possible causes are wiring harness failure or ignition coil (T1/4) defective. Repair as necessary.
scientia non olet · About LEMON Manuals