DTC P0037:00: Notes

DTC P0037:00

HO2S heater control circuit low input

DETECTION CONDITION

The PCM monitors the HO2S heater output voltage. If the PCM turns the HO2S heater off but the HO2S heater circuit remains low voltage, the PCM determines that the HO2S heater circuit has a malfunction.
Diagnostic support note
This is a continuous monitor (A/F sensor heater, HO2S heater).
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

HO2S connector or terminal malfunction
Short to ground or open circuit in HO2S heater power supply circuit
- Short to ground in wiring harness between ignition switch terminal C⁽¹⁾/relay block terminal 1B⁽²⁾ and HO2S terminal C
- HEGO 5 A fuse malfunction
- Open circuit in wiring harness between ignition switch terminal C⁽¹⁾/relay block terminal 1B⁽²⁾ and HO2S terminal C
Short to ground in wiring harness between HO2S terminal D and PCM terminal 2B
HO2S heater malfunction
PCM connector or terminal malfunction
Open circuit in wiring harness between HO2S terminal D and PCM terminal 2B
PCM malfunction

⁽¹⁾	Vehicles without advanced keyless entry and push button start system

⁽²⁾	Vehicles with advanced keyless entry and push button start system