Signal Too Low - Intermittent Fault

ECM-280A FRONT HEATED OXYGEN SENSOR (HO2S), FAULTY SIGNAL
SIGNAL TO LOW - INTERMITTENT FAULT

Checking connector and wiring




CAUTION!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Check Heated Oxygen Sensor (HO2S) connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Intermittent Faults and loose connections according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Check signal cable (-) between Heated Oxygen Sensor (HO2S) # 5 and control module # A42 (# A42) and the cable for calibration current between Heated Oxygen Sensor (HO2S) # 2 and control module (HO2S) # A28 (# A28) for an intermittent open-circuit according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Check calibration current power cable between Heated Oxygen Sensor (HO2S) # 2 and control module # A28 (# A28) and power Supply for pump current between Heated Oxygen Sensor (HO2S) # 6 and control module # A24 (# A24) for an intermittent short-circuit to each other according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Other information
- Connecting the breakout box/accessing the control module Connecting the Breakout Box (ECM)
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.