• | 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, P0050, P0053, P0059, P0135, P0155, P0443, P0660, P2070, P2078 | P0030, P0053, P0135 | P0030, P0053, P0135 | P0690, P2070 | P0135 |
HO2S Heater Low Control | P0030, P0135 | P0030, P0053, P0135 | P0030, P0053, P0135 | P0030, P0135, P0690, P2070 | P0135 |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S Heater Voltage Supply | Opens fuse P0036, P0054, P0056, P0060, P0141, P0161 | P0036, P0054, P0141 | P0036, P0054, P0141 | P0690 | P0141 |
HO2S Heater Low Control | P0036, P0141 | P0030, P0054, P0141 | P0036, P0054, P0141 | P0036, P0141, P0690 | P0141 |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S Heater Voltage Supply | Approximately 0.5-2.0 A | 0.00 A | 0.00 A | Approximately 0.5-2.0 A |
HO2S Heater Voltage Supply | 7-100% | 7% | 7% | 7-100% |
HO2S Heater Low Control | Approximately 0.5-2.0 A | 0.00 A | 0.00 A | 0.00 A |
HO2S Heater Low Control | 7-100% | 7% | 7% | 7% |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S Heater Voltage Supply | Approximately 0.5-2.0 A | 0.00 A | 0.00 A | Approximately 0.5-2.0 A |
HO2S Heater Voltage Supply | 7-100% | 7% | 7% | 7-100% |
HO2S Heater Low Control | Approximately 0.5-2.0 A | 0.00 A | 0.00 A | 0.00 A |
HO2S Heater Low Control | 7-100% | 7% | 7% | 7% |
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 engine is cranking or running. |
• | The engine speed parameter is greater than 400 RPM. |
• | The system voltage is between 10-18 volts. |
• | DTCs P0112, P0113, P0116, P0117, P0118, P0128, P1258, P2610 are not set. |
• | The ignition is OFF for more than 8 hours. |
• | The difference between the start-up engine coolant temperature (ECT) and the intake air temperature (IAT) is less than 8°C (14.4°F). |
• | The ECT Sensor parameter is between -30 and +45°C (-22 and +133°F) at engine start-up. |
• | The system voltage is between 10-18 volts. |
• | This diagnostic runs one time per valid cold start when the above conditions are met. |
• | DTCs P0030, P0053, P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135, P2176, are not set. |
• | The system voltage is between 10-18 volts. |
• | The scan tool special functions are not active. |
• | The Engine Run Time parameter is more than 180 seconds. |
• | The ECT Sensor parameter is at least 65°C (149°F). |
• | The Engine Speed parameter is between 500-3,000 RPM. |
• | The MAF Sensor parameter is between 5-30 g/s. |
• | The above conditions have been met for more than 2 seconds. |
• | DTCs P0036, P0054, P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set. |
• | The system voltage is between 10-18 volts. |
• | The scan tool special functions are not active. |
• | The Engine Run Time parameter is at least 180 seconds. |
• | The ECT parameter is at least 65°C (149°F). |
• | The Engine Speed parameter is between 500-3,000 RPM. |
• | The MAF Sensor parameter is between 5-30 g/s. |
• | The above conditions have been met for more than 2 seconds. |
• | The ECM detects that the HO2S heater control circuit status is incorrect for more than 2 seconds. |
• | This diagnostic runs continuously. |
The ECM detects that the HO2S heater calculated resistance is not between 1.3-7.5 ohms at engine start-up for 1 second.
The ECM detects that the HO2S heater calculated resistance is not between 1.9-8.6 ohms at engine start-up for 1 second.
• | The HO2S heater current is less than 0.25 amp or more than 3.13 amps for more than 8 seconds, twice within a 1-minute test period. |
• | The test is run 2 times per trip. |
• | The HO2S heater current is less than 0.43 amp or more than 2.9 amp for more than 8 seconds, twice within a 1-minute test period. |
• | The test is run 2 times per trip. |
DTCs P0030, P0036, P0053, P0054, P0135, and P0141 are Type B DTCs.
DTCs P0030, P0036, P0053, P0054, P0135, and P0141 are Type B DTCs.
When using a high impedance, low current draw, test lamp to load the heater circuit, the test lamp flash may be dim, the scan tool Heater Command parameter may indicate 7 percent, and the Heater parameter may indicate 0 amps. This is a normal condition.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Important: 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 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 ECM. |
Important:
• 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 10 ohms 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 ohm. If the circuits test normal, replace the ECM. |
Notice: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice in the Preface section.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for control module replacement, setup, and programming |