Diagnostic Procedure
DIAGNOSTIC PROCEDURES - P2096-DOWN STREAM FUEL SYSTEM 1/2 LEAN
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
NOTE:
Check the vehicle repair history. If the O2 has been replace ensure that the O2 sensor was properly installed and meets OEM specification.
NOTE:
Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Ignition on, engine not running.With the DRBIII®, read DTCs and record the related Freeze Frame data.Is the Good Trip Counter displayed and equal to zero?Yes --> Go To 2No --> Refer to the INTERMITTENT CONDITION SYMPTOM .Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 2 | Turn the ignition off.
WARNING:
To avoid personal injury from the exhaust system being hot, allow the exhaust to cool down to a safe temperature before performing a physical inspection. Visually and Physically inspect the exhaust system for holes, cracks and/or blockage. Is the exhaust system is good condition? Yes --> Go To 3 No --> Repair or Replace as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 3 | Check for any of the following conditions/mechanical problems. AIR INDUCTION SYSTEM - must be free from leaks. ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector Are there any engine mechanical problems? Yes --> Repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Go To 4 |
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| 4 | Ignition on, engine not running. Disconnect the O2 Sensor harness connector. With the DRBIII®, monitor the O2 Sensor voltage. The O2 Sensor voltage should read 5.0 volts on the DRBIII® with the connector disconnected. Using a jumper wire, jump the O2 Signal circuit to the O2 Return circuit at the O2 Sensor harness connector.
NOTE:
The voltage should drop from 5.0 volts to 2.5 volts with the jumper wire in place.
NOTE:
Perform the following steps on the 02 sensor the applies to the DTC that set. Did the O2 Sensor volts change from 5.0 volts to 2.5 volts? Yes --> Replace the O2 Sensor Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Go To 5 |
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| 5 | Turn the ignition off. Disconnect the O2 Sensor harness connector. Ignition on, engine not running. With the DRBIII®, monitor the O2 Sensor voltage. Is the voltage above 4.8 volts? Yes --> Go To 6 No --> Check the O2 Signal circuit for a short to ground, open, or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 6 | Turn the ignition off. Disconnect the O2 Sensor harness connector. Ignition on, engine not running. Measure the voltage on the O2 Return circuit in the O2 Sensor harness connector. Is the voltage at 2.5 volts? Yes --> Check the fuel system for contaminants. Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Check the O2 Return circuit for a short to ground, open, or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
All |