• | 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 provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S Heater Voltage Supply | Opens fuse | P0030, P0036, P0053, P0054, P0135, P0141 | P0030, P0036, P0135, P0141 | -- | P0135, P0141 |
HO2S Heater Low Control | P0030, P0036 | P0030, P0036, P0053, P0054, P0135, P0141 | P0030, P0036, P0135, P0141 | P0030, P0036, P0135, P0141 | P0135, P0141 |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S Heater Low Control | 1-2A | 0A | 0A | 0A |
HO2S Heater Voltage Supply | 1-2A | 0A | 0A | 1-2A |
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the engine control module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.
The ECM monitors the voltage on the HO2S heater low control circuit for heater fault diagnosis.
The ECM determines the temperature by measuring the current flow through the heater and calculating the resistance. Based on the resistance, the ECM can predict the sensor temperature. The HO2S uses pulse width modulation (PWM) to control the heater operation. The ECM calculates the heater resistance on a cold start. This diagnostic will only run once per ignition cycle.
• | The Ignition 1 Signal parameter is between 10-18V. |
• | The engine speed is more than 400 RPM. |
• | DTC P0030 and P0036 runs continuously when the above conditions are met for 1 second. |
• | DTCs P0112, P0113, P0117, P0118 are not set. |
• | The engine is started. |
• | The ignition is OFF for more than 10 hours. |
• | The ECT Sensor parameter is between 0-40°C (32-104°F) at engine start-up. |
• | The ECT Sensor parameter minus the IAT Sensor parameter is less than 8°C (14°F) at engine start-up. |
• | DTCs P0053 and P0054 run once per drive cycle when the above conditions are met. |
• | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0443, P1516, P2101, P2119, P2135, P2176 are not set. |
• | The ECT Sensor parameter is more than 70°C (158°F). |
• | The Ignition 1 Signal parameter is between 10-18V. |
• | The MAF Sensor parameter is between 5-25 g/s. |
• | The Engine Run Time parameter is more than 60 seconds. |
• | The Engine Speed parameter is between 500-3,000 RPM. |
• | DTC P0135 runs the heater current test twice per drive cycle when the above conditions are met for 2 seconds. |
• | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0443, P1516, P2101, P2119, P2135, P2176 are not set. |
• | The ECT Sensor parameter is more than 70°C (158°F). |
• | The Ignition 1 Signal parameter is between 10-18V. |
• | The MAF Sensor parameter is between 5-25 g/s. |
• | The Engine Run Time parameter is more than 60 seconds. |
• | The Engine Speed parameter is between 500-3,000 RPM. |
• | DTC P0141 runs the heater current test twice per drive cycle when the above conditions are met for 2 seconds. |
• | The ECM detects that the affected HO2S heater low control circuit is not within a specified range. |
• | DTCs P0030 and P0036 set within 3 seconds when the above condition is met. |
• | The ECM detects that the affected HO2S heater low control circuit is not within a specified range at engine start-up. |
• | DTCs P0053 and P0054 set within one second when the above condition is met. |
• | The ECM detects that the HO2S 1 Heater parameter is more than 2.5 amps or less than 0.25 amp. |
• | DTC P0135 sets within 30 seconds during the heater current test when the above condition is met. |
• | The ECM detects that the HO2S 2 Heater parameter is more than 2.5 amps or less than 0.25 amp. |
• | DTC P0141 sets within 30 seconds during the heater current test when the above condition is met. |
DTC P0030, P0036, P0053, P0054, P0135, P0141 are Type B DTCs.
DTC P0030, P0036, P0053, P0054, P0135, P0141 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
⇒ | If the test lamp does not illuminate, test the HO2S heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the HO2S heater voltage supply circuit fuse is open, test all components connected to the fuse and replace as necessary. |
⇒ | If the lamp illuminates, test the HO2S heater low control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. |
⇒ | If the test lamp is not ON steady or flashing, test the HO2S heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
Note:
• The output driver should detect a short to voltage and turn OFF. If a resistance fault is present the driver will remain ON and the scan tool will display more than 0.0 amp. Less than 10Ω may set a DTC. • Performing this test may set additional DTCs.
⇒ | If more than the specified range, test the HO2S heater voltage supply and HO2S heater low control circuits for more than 1 Ω. If the circuits test normal, replace the ECM. |
Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution in the Preface section.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for replacement, setup, and programming |