Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information EFI-153

EFI-153 Rear heated oxygen sensor (HO2S), signal

Condition




The rear heated oxygen sensor (HO2S) must be at operating temperature and have the correct output voltage to affect fuel trim and monitor the three-way catalytic converter (TWC) and front heated oxygen sensor (HO2S). Monitoring of the heated oxygen sensor (HO2S) function starts approximately 3 minutes after heated oxygen sensor (HO2S) heating starts. Diagnostic trouble code (DTC) EFI-153 is stored if there is a fault in the front or rear heated oxygen sensors (HO2S) or their cabling that affects the output voltage from the rear heated oxygen sensor (HO2S).

Substitute value
- twin heated oxygen sensor (HO2S) control disabled
- three-way catalytic converter (TWC) diagnostic disabled.

Possible source

Signal too high:
- short-circuit to supply voltage in front heated oxygen sensor (HO2S) signal cable (+)
- short-circuit to supply voltage in front heated oxygen sensor (HO2S) signal cable (-)
- short-circuit to supply voltage in rear heated oxygen sensor (HO2S) signal cable (+)
- short-circuit to supply voltage in rear heated oxygen sensor (HO2S) signal cable (-)
- defective front heated oxygen sensor (HO2S)
- defective rear heated oxygen sensor (HO2S).

Signal too low:
- short-circuit to ground in front heated oxygen sensor (HO2S) signal cable (+)
- short-circuit to ground in front heated oxygen sensor (HO2S) signal cable (-)
- short-circuit to ground in rear heated oxygen sensor (HO2S) signal cable (+)
- short-circuit to ground in rear heated oxygen sensor (HO2S) signal cable (-)
- defective front heated oxygen sensor (HO2S)
- defective rear heated oxygen sensor (HO2S).

Signal missing:
- open-circuit in signal cable (+)
- open-circuit in signal cable (-)
- defective rear heated oxygen sensor (HO2S).

Faulty signal:
- signal cable (+) short-circuited to signal cable (-)
- defective rear heated oxygen sensor (HO2S).

Fault symptom[s]
- none.