This diagnostic applies only to vehicles built with Delphi heated oxygen
sensors. To identify the heated oxygen sensor refer to
Oxygen Sensor Identification (4.8L/5.3L/6.0L)
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (HO2S) activity for 100 seconds. During the monitor period, the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich and adds the amount of time it took to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a diagnostic trouble code (DTC) sets.
The PCM determines the lean to rich transition when the HO2S voltage changes from less than 300 mV to more than 600 mV. The PCM determines the rich to lean transition when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly is most likely defective. Replace the HO2S.
• | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0200, P0300, P0401, P0404, P0405, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1404, P1415, P1416, P1514, P1515, P1516, P1517, or P1518 are not set. |
• | The engine coolant temperature (ECT) is more than 65°C (149°F). |
• | The engine run time is more than 160 seconds. |
• | The EVAP purge solenoid command is more than 0 percent. |
• | The mass air flow (MAF) is between 23-50 g/s. |
• | The engine speed is between 1,200-3,000 RPM. |
• | Vehicles without throttle-actuated control (TAC), the throttle position (TP) is more than 5 percent. |
• | Vehicles with throttle-actuated control (TAC), the throttle position (TP) indicated angle is 5 percent more than the value observed at idle. |
• | The loop status is closed. |
• | The ignition 1 signal is between 9-18 volts. |
• | The fuel tank level remaining is more than 10 percent. |
• | Intrusive tests are not in progress. |
• | The scan tool output controls are not active. |
• | The rich-to-lean and lean-to-rich response time average is more than a calibrated value. |
• | The above conditions are met for 100 seconds. |
• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
• | This diagnostic only runs once per ignition cycle. |
• | A malfunction in the HO2S heater circuits causes a DTC to set. Check the HO2S heater circuits for intermittent opens and faulty connections. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
• | An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks or contamination. Refer to Heated Oxygen Sensor Wiring Repairs in Wiring Systems. |
• | Using the Freeze Frame and Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass or a fail. Operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature, etc. that you observed. This will isolate when the DTC failed. For an intermittent condition, refer to Intermittent Conditions . |
The numbers below refer to the step numbers on the diagnostic table.
This step determines if the fault is present. This test may take 5 minutes for the diagnostic to run.
When DTCs P0133 and P0153 are set at the same time, it is a good indication that a fuel contamination problem is present.
An exhaust leak 6-12 inches away from the HO2S can cause a DTC to set.
This step tests whether a good ground circuit is available.
This step tests the integrity of the low signal circuit to the PCM.
This step tests the integrity of the low signal circuit to the PCM.
Certain RTV silicone gasket materials give off vapors that can contaminate the HO2S. There is also a possibility of silicone-contamination caused by silicone in the fuel. If the sensors appear to be contaminated by silicone and all the silicone sealant is a non silicone base, advise the customer to try a different fuel company. A missing fuel filler restrictor indicates the customer may have used leaded fuel.
Step | Action | Values | Yes | No | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Important: This diagnostic applies only to vehicles built with Delphi heated oxygen
sensors. To identify the heated oxygen sensor, refer to
| ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
Important: If any DTCs are set except P0133 or P0153, refer to those DTCs before proceeding with this diagnostic table.
Did DTC P0133 fail this ignition? | -- | Go to Step 3 | Go to Diagnostic Aids | |||||||||
Did DTC P0153 also fail this ignition? | -- | Go to Step 8 | Go to Step 4 | |||||||||
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 5 | |||||||||
Inspect the following items:
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 6 | |||||||||
Is the voltage within the specified range? | 350-550 mV | Go to Step 7 | Go to Step 10 | |||||||||
Is the voltage less than the specified value? | 200 mV | Go to Step 13 | Go to Step 9 | |||||||||
Important: Determine and correct the cause of the contamination before replacing
a sensor. Inspect for the following conditions:
Replace the affected heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement? | -- | Go to Step 14 | -- | |||||||||
9 |
Is the voltage near the specified value? | 5 V | Go to Step 12 | Go to Step 11 | ||||||||
10 | Repair the high signal circuit for a short to ground or a short to voltage. Refer to Heated Oxygen Sensor Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
11 | Repair the open in the HO2S low signal circuit or repair the poor PCM connections. Refer to Heated Oxygen Sensor Wiring Repairs or to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
12 | Repair the HO2S high signal circuit for an open or repair the poor PCM connections. Refer to Heated Oxygen Sensor Wiring Repairs or to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
13 | Replace the HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||||
14 |
Does the DTC run and pass? | -- | Go to Step 15 | Go to Step 2 | ||||||||
15 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
This diagnostic applies only to vehicles built with Denso heated oxygen
sensors. To identify the heated oxygen sensor refer to
Oxygen Sensor Identification (4.8L/5.3L/6.0L)
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (HO2S) activity for 100 seconds. During the monitor period, the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich and adds the amount of time it took to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a diagnostic trouble code (DTC) sets.
The PCM determines the lean to rich transition when the HO2S voltage changes from less than 300 mV to more than 600 mV. The PCM determines the rich to lean transition when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly is most likely defective. Replace the HO2S.
• | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0200, P0300, P0401, P0404, P0405, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1404, P1415, P1416, P1514, P1515, P1516, P1517, or P1518 are not set. |
• | The engine coolant temperature (ECT) is more than 65°C (149°F). |
• | The engine run time is more than 160 seconds. |
• | The EVAP purge solenoid command is more than 0 percent. |
• | The mass air flow (MAF) is between 23-50 g/s. |
• | The engine speed is between 1,200-3,000 RPM. |
• | Vehicles without throttle-actuated control (TAC), the throttle position (TP) is more than 5 percent. |
• | Vehicles with throttle-actuated control (TAC), the throttle position (TP) indicated angle is 5 percent more than the value observed at idle. |
• | The loop status is closed. |
• | The ignition 1 signal is between 9-18 volts. |
• | The fuel tank level remaining is more than 10 percent. |
• | Intrusive tests are not in progress. |
• | The scan tool output controls are not active. |
• | The rich-to-lean and lean-to-rich response time average is more than a calibrated value. |
• | The above conditions are met for 100 seconds. |
• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
Important: Never solder the HO2S wires. For proper wire and connector repairs, refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Check for the following conditions:
• | Inspect for an improperly installed air cleaner outlet duct. |
• | Inspect the air cleaner outlet duct for a collapsed duct, restrictions, or a missing or plugged air filter. |
• | Inspect the throttle body and the intake manifold for vacuum leaks. |
• | Inspect for a damaged or blocked throttle body inlet. |
• | Inspect the exhaust system for corrosion, leaks, or loose or missing hardware. Refer to Exhaust Leakage in Engine Exhaust. |
• | Verify that the HO2S is installed securely and the pigtail harness is not contacting the exhaust manifold or wires. |
• | Check for any HO2S contamination. |
• | Inspect the vacuum hoses for splits, kinks, and proper connections. |
• | Test for excessive water, alcohol, or other contaminants in the fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . |
• | Verify that the PCM sensor grounds are clean, tight, and properly positioned. |
An intermittent may be caused by any of the following conditions:
• | A poor connection |
• | Rubbed through wire insulation |
• | A broken wire inside the insulation |
Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If a repair is necessary, then refer to Wiring Repairs or Connector Repairs in Wiring Systems.
The numbers below refer to the step numbers on the diagnostic table.
HO2S contamination is indicated if multiple response, switching or time ratio HO2S DTCs are set.
An HO2S contaminated by silicon will have a white, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of unapproved silicon RTV engine gasket material or the use of silicon based sprays or fluids within the engine.
If the cause of this contamination is not corrected, the replacement HO2S will also be contaminated.
Even small exhaust leaks can cause slow response from the HO2S.
An HO2S contaminated by silicon will have a white, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of unapproved silicon RTV engine gasket material or the use of silicon based sprays or fluids within the engine. If the cause of this contamination is not corrected, the replacement HO2S will also be contaminated.
If the voltage observed in step 8 is less than the range specified, a short between the high signal circuit and the low reference circuits, or a short between the high signal circuit and ground is indicated. With the HO2S and the PCM disconnected, the resistance between the high signal circuit and low reference circuits and the resistance between the high signal circuit and ground should measure infinite.
If the voltage observed in step 8 is more than the range specified, a short between the high circuit and an ignition voltage source is indicated.
If the voltage observed in step 9 is not less than the voltage specified, a high resistance high signal or low reference circuit is indicated.
Good circuit continuity measures less than 5 ohms with the PCM and the sensor disconnected. Measure between the PCM connector and the HO2S connector. Ensure the PCM terminal contact is good.
Step | Action | Values | Yes | No | ||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Important: This diagnostic applies only to vehicles built with Denso heated oxygen
sensors. To identify the heated oxygen sensor, refer to
| ||||||||||||||||||||||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||||||||||||||||||||||
In addition to this DTC, check for the following HO2S DTCs:
Are any of the above listed HO2S DTCs set? | -- | Go to Step 4 | Go to Step 3 | |||||||||||||||||||||||||||||
3 | Are any powertrain component DTCs set? | -- | Go to Step 5 | |||||||||||||||||||||||||||||
Has the contamination source been removed and the affected sensors replaced? | -- | Go to Step 18 | -- | |||||||||||||||||||||||||||||
5 |
Did this diagnostic test run and fail this ignition? | -- | Go to Step 7 | Go to Step 6 | ||||||||||||||||||||||||||||
6 |
Did you find and correct the condition? | -- | Go to Step 18 | Go to Diagnostic Aids | ||||||||||||||||||||||||||||
Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 8 | |||||||||||||||||||||||||||||
8 |
Is the HO2S voltage within the specified range? | 351-551 mV | Go to Step 9 | Go to Step 13 | ||||||||||||||||||||||||||||
9 |
Is the HO2S voltage less than the specified value? | 20 mV | Go to Step 10 | Go to Step 14 | ||||||||||||||||||||||||||||
10 |
Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 15 | ||||||||||||||||||||||||||||
11 | Connect the test lamp between the ignition 1 voltage circuit terminal of the HO2S heater and the ground circuit terminal of the HO2S heater. Does the test lamp illuminate | -- | Go to Step 12 | Go to Step 16 | ||||||||||||||||||||||||||||
Did you complete the repair? | -- | Go to Step 17 | -- | |||||||||||||||||||||||||||||
Repair the short between the HO2S high signal and the low reference circuits, or repair the short between the HO2S high signal circuit and an ignition voltage source. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | |||||||||||||||||||||||||||||
Did you complete the repair? | -- | Go to Step 18 | -- | |||||||||||||||||||||||||||||
15 | Repair the ignition positive voltage circuit of the HO2S heater. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||||||||||||||||||||||||
16 | Repair the HO2S heater ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||||||||||||||||||||||||
17 | Replace the HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 . Did you complete the repair? | -- | Go to Step 18 | -- | ||||||||||||||||||||||||||||
18 |
Does the DTC run and pass? | -- | Go to Step 19 | Go to Step 2 | ||||||||||||||||||||||||||||
19 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |