DTC P2097: Post Catalyst Fuel Trim System High 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. Observe the Freeze Frame/Failure Records for this DTC. 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 3 | Go to Diagnostic Aids |
| 3 | 1. Operate the engine above 1,200 rpm for 30 seconds. 2. Observe the rear HO2S voltage with a scan tool. Is the voltage less than the specified value? | 1,050 mV | Go to Step 6 | Go to Step 4 |
| 4 | 1. 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 10 | Go to Step 5 |
| 5 | Test the HO2S signal circuit for a short to voltage. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 12 |
| 6 | 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 13 | Go to Step 7 |
| 7 | 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 13 | Go to Step 8 |
| 8 | 1. Turn the ignition OFF. 2. Disconnect the heated oxygen sensors. 3. Inspect the front and rear heated oxygen sensors for the following conditions: - For damaged wiring between the HO2S and the ECM-An intermittent circuit condition may cause this DTC to set. - For terminal corrosion or water intrusion in the HO2S harness connectors. - For the correct terminal tension. - The HO2S is securely installed. - For any exhaust leaks. 4. Repair as necessary. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 9 |
| 9 | 1. Disconnect the ECM. 2. Test the front heated oxygen sensor circuits for being shorted together between the HO2S connector and the ECM. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 11 |
| 10 | Test for shorted terminals and for poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 15 |
| 11 | Test for shorted terminals and for poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 11 |
| 12 | Test for shorted terminals and for poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 16 |
| 13 | Repair the circuit as necessary. Did you complete the repair? | - | Go to Step 17 | - |
| 14 | Replace the HO2S Sensor 1. Did you complete the replacement? | - | Go to Step 17 | - |
| 15 | Replace the HO2S Sensor 2. Did you complete the replacement? | - | Go to Step 17 | - |
| 16 | Replace the ECM. Did you complete the replacement? | - | Go to Step 17 | - |
| 17 | 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 18 |
| 18 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |