• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
HO2S Bank 1 Sensor 1 Signal | P0131 | P0130, P0134 | P0132 | P0130, P0133 |
HO2S Bank 1 Sensor 2 Signal | P0137 | P0140 | P0138 | P0139 |
HO2S Bank 2 Sensor 1 Signal | P0151 | P0150, P0154 | P0152 | P0150, P0153 |
HO2S Bank 2 Sensor 2 Signal | P0157 | P0160 | P0158 | P0159 |
Low Reference | -- | P0130, P0150, | P0134, P0140, P0154, P0160 | -- |
The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust system and provides more information than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine control module (ECM) supplies a voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell in order to maintain a constant voltage in the oxygen sensing cell. The ECM monitors the voltage variation in the sensing cell and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or oxygen ion flow, to the pumping cell. By measuring the amount of current required to maintain the voltage in the sensing cell, the ECM can determine the concentration of oxygen in the exhaust. The HO2S voltage is displayed as a lambda value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1. When the fuel system is lean, the oxygen level will be high and the lambda signal will be high or greater than 1. When the fuel system is rich, the oxygen level will be low, and the lambda signal will be low or less than 1. The ECM uses this information to maintain the correct air/fuel ratio. If the ECM detects that the HO2S signal voltage is low, this DTC sets.
• | The engine is operating. |
• | The ignition 1 voltage is between 10.7-18 volts. |
• | DTC P0130 and P0150 run continuously once the above conditions are met. |
The ECM detects that the HO2S signal voltage is out of range for greater than 4 seconds.
DTCs P0130 and P0150 are Type B DTCs.
DTCs P0130 and P0150 are Type B DTCs.
• | The front wide band sensors do not toggle or switch like a switching HO2S. The front HO2S signals will be relatively stable for an idling engine. |
• | The following table illustrates the typical voltages for the HO2S circuits: |
HO2S Circuit | Voltage | ||||
---|---|---|---|---|---|
| |||||
Heater Control | 4.6-5.0 V | ||||
Heater Supply Voltage | B+ | ||||
Reference Voltage | 2.6-3.1 V | ||||
Low Reference | 2.2-2.7 V | ||||
Pump Current | 2.5-3.0 V | ||||
Input Pump Current | 2.5-3.0 V |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If less than the specified range, test the reference voltage circuit and the low reference circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. |
⇒ | If greater than the specified range, test the reference voltage circuit and the low reference circuit for a short to voltage. If the circuits test normal, replace the ECM. |
⇒ | If less than the specified range, test the input pump current circuit and the pump current circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. |
⇒ | If greater than the specified range, test the input pump current circuit and the pump current circuit for a short to voltage. If the circuits test normal, replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |