HO2S Heater Monitor
OBD System Description - HO2S Heater MonitorO2_11_HeaterShortLow
DTC Description / Detecting Condition / Confirmation Procedure
P0031 refer to P0031
Monitor Strategy Description
Detects a short to ground or open circuit of O2 sensor heater circuit output.
Malfunction Criteria
Output driver IC internal feedback voltage less than state calls for high voltage = TRUE
Enable Conditions
No disabling Faults Present = FALSE
AND Engine Running = RUN
AND Ignition Voltage >= 11 V
AND Ignition Voltage <= 16 V
AND Enable Time delay >= 0.5 s
Time required
Detection Time
5.00 seconds failure out of 9.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
40 test failures within 80 test samples at 125. ms loop time
O2_11_HeaterShortHigh
DTC Description / Detecting Condition / Confirmation Procedure
P0032 refer to P0032
Monitor Strategy Description
Detects a short to battery O2 sensor heater circuit output.
Malfunction Criteria
Output driver IC internal feedback voltage greater than state calls for low voltage = TRUE
Enable Conditions
No disabling Faults Present = FALSE
AND Engine Running = RUN
AND Ignition Voltage >= 11 V
AND Ignition Voltage <= 16 V
AND Enable Time delay >= 0.5 s
Time required
Detection Time
5.00 seconds failure out of 9.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
40 test failures within 80 test samples at 125. ms loop time
O2_12_HeaterShortLow
DTC Description / Detecting Condition / Confirmation Procedure
P0037 refer to P0037
Monitor Strategy Description
Detects a short to ground or open circuit of O2 sensor heater circuit output.
Malfunction Criteria
Output driver IC internal feedback voltage less than state calls for high voltage = TRUE
Enable Conditions
No disabling Faults Present = FALSE
AND Engine Running = RUN
AND Ignition Voltage >= 11 V
AND Ignition Voltage <= 16 V
AND Enable Time delay >= 0.5 s
Time required
Detection Time
5.00 seconds failure out of 9.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
40 test failures within 80 test samples at 125. ms loop time
O2_12_HeaterShortHigh
DTC Description / Detecting Condition / Confirmation Procedure
P0038 refer to P0038
Monitor Strategy Description
Detects a short to battery of O2 sensor heater circuit output.
Malfunction Criteria
Output driver IC internal feedback voltage greater than state calls for low voltage = TRUE
Enable Conditions
No disabling Faults Present = FALSE
AND Engine Running = RUN
AND Ignition Voltage >= 11 V
AND Ignition Voltage <= 16 V
AND Enable Time delay >= 0.5 s
Time required
Detection Time
5.00 seconds failure out of 9.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
40 test failures within 80 test samples at 125. ms loop time
O2_11_Heater(HeaterCurrent)
DTC Description / Detecting Condition / Confirmation Procedure
P0135 refer to P0135
Monitor Strategy Description
Compares the current that is passing through the O2 Heater to a low limit.
Malfunction Criteria
Filtered O2 Heater Current < See table below.
KtEOSD_I_11_HtrCurrFiltThrsh.data
Enable Conditions
Ignition ON = ON
AND Engine Running Long Enough > 60 s
AND Minimum Heater Duty Cycle Commanded > 0.1%
AND Commanded Duty Cycle change over time small enough < 0.05%
AND Heater Duty Cycle State reached Steady State = Steady State (4)
AND No disabling faults present = FALSE
AND Conditions met for enough time >= 0.375 s
Time required
Detection Time
20.00 seconds failure out of 39. seconds sample period
Continuous Monitoring every 1000. ms loop time
Detection Samples
20 test failures within 40 test samples at 1000. ms loop time
O2_12_Heater(HeaterCurrent)
DTC Description / Detecting Condition / Confirmation Procedure
P0141 refer to P0141
Monitor Strategy Description
Compares the current that is passing through the O2 Heater to a low limit.
Malfunction Criteria
Filtered O2 Heater Current < See table below.
KtEOSD_I_12_HtrCurrFiltThrsh.data
Enable Conditions
Ignition ON = ON
AND Engine Running Long Enough > 30 s
AND Minimum Heater Duty Cycle Commanded > 0.1%
AND Commanded Duty Cycle change over time small enough < 0.05%
AND Heater Duty Cycle State reached Steady State = Steady State (4)
AND No disabling faults present = FALSE
AND Conditions met for enough time >= 0.375 s
Time required
Detection Time
60.00 seconds failure out of 119. seconds sample period
Continuous Monitoring every 1000. ms loop time
Detection Samples
60 test failures within 70 test samples at 1000. ms loop time