LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercedes Benz >> 1988 >> 560SL >> Repair and Diagnosis >> Engine Performance >> System >> Cis-E System >> Trouble Shooting >> Testing With Impulse Counter >> Code 5, Oxygen Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Code 5, Oxygen Sensor

  1. With engine at operating temperature and at idle, CIS-E control unit connected. Connect voltmeter negative lead socket No. 7 and positive lead to No. 8 of socket box. Voltage should fluctuate between 0.1-0.9 volts. If not, check O2 sensor wiring circuit.
  2. Disconnect O2 sensor signal connector and ground terminal. Connect voltmeter negative lead to socket No. 7 and O2 sensor signal connector socket. With engine at idle, voltmeter reading should be greater than 450 millivolt. If not, replace O2 sensor.
  3. Turn ignition "OFF". Unplug CIS-E control unit connector. Connect ohmmeter between socket No. 7 and 8 of socket box. Ohmmeter should read infinity. Connect ohmmeter to socket No. 8 and O2 wiring harness pin. Resistance should be less than one ohm. If not, check for open circuit.
scientia non olet · About LEMON Manuals