DTC P2096: Post Catalyst Fuel Trim System Low Limit: Troubleshooting
TROUBLESHOOTING CHART
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Perform an On-Board Diagnostic (OBDII) System Check. Is the system check complete? | - | Go to Step 2 | Go to On-Board Diagnostic (OBD II) System Check |
| 2 | 1.Allow the engine to reach operating temperature. 2.Operate the vehicle within the parameters specified in Conditions for Setting the DTC. 3.Observe the diagnostic trouble code (DTC) information with a scan tool. Did the DTC fail this ignition? | - | Go to Step 4 | Go to Step 3 |
| 3 | Turn the ignition OFF for 30 seconds. 3.Start the engine. 4.Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | - | Go to Step 4 | Go to Diagnostic Aids |
| 4 | 2.Observe the rear heated oxygen sensor (HO2S) voltage with a scan tool. Is the voltage more than the specified value? | 60 mV | Go to Step 7 | Go to Step 5 |
| 5 | Turn the ignition OFF. 2.Disconnect the HO2S. 3.Turn the ignition ON, with the engine OFF. 4.Observe the HO2S voltage parameter with a scan tool. Is the voltage within the specified range? | 350 - 550 mV | Go to Step 11 | Go to Step 6 |
| 6 | Test the HO2S signal circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 13 |
| 7 | Move the related HO2S harnesses for the front sensor between the HO2S harness connector and the engine control module (ECM) while monitoring the HO2S lambda parameter. Does the HO2S parameter change abruptly while moving the related harnesses? | - | Go to Step 14 | Go to Step 8 |
| 8 | Move the related HO2S harnesses for the rear sensor between the HO2S harness connector and the ECM while monitoring the HO2S voltage parameter. Does the HO2S parameter change abruptly while moving the related harnesses? | - | Go to Step 14 | Go to Step 9 |
| 9 | 1. Turn the ignition OFF. 2. Disconnect the front and rear HO2S. 3. Inspect the front and rear HO2S for the following conditions: - Damaged wiring between the HO2S and the ECM. - Terminal corrosion or water intrusion in the HO2S harness connectors. - The correct terminal tension. - The HO2S is securely installed. - Any exhaust leaks. 4. Repair as necessary. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 10 |
| 10 | 1. Disconnect the ECM. 2. Test the front HO2S circuits for being shorted together between the HO2S connector and the ECM. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 12 |
| 11 | Test for shorted terminals and for poor connections at the HO2S. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 16 |
| 12 | Test for shorted terminals and for poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 15 |
| 13 | Test for shorted terminals and for poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 18 | Go to Step 17 |
| 14 | Repair the circuit as necessary. Did you complete the repair? | - | Go to Step 18 | - |
| 15 | Replace the HO2S Sensor 1. Did you complete the replacement? | - | Go to Step 18 | - |
| 16 | Replace the HO2S Sensor 2. Did you complete the replacement? | - | Go to Step 18 | - |
| 17 | Replace the ECM. Did you complete the replacement? | - | Go to Step 18 | - |
| 18 | 1. Clear the DTCs with a scan tool. 2. Turn the ignition OFF for 30 seconds. 3. Start the engine. 4. Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 19 |
| 19 | Check if any additional DTCs are set. Are any DTCs displayed that have not been diagnosed? | - | Go to applicable DTC table | System OK |