P2097

P2097-DOWNSTREAM FUEL TRIM SYSTEM 1 RICH





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With the engine running in closed loop mode, the ambient/battery temperature above (-7°C) 20°F, altitude below 8500 ft.

- Set Condition:
If the PCM multiplies short term compensation by long term adaptive as well as a purge fuel multiplier and the result is below a certain value for 30 seconds over two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

NOTE: Check the vehicle repair history. If the 1/2 O2 Sensor has been replaced make sure 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.

1. Ignition on, engine not running.
2. With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. . Intermittent Condition Test
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. CHECKING THE EXHAUST SYSTEM FOR LEAKS
1. Perform the diagnostic procedure for CHECKING THE EXHAUST SYSTEM FOR LEAKS. . Checking the Exhaust System For Leaks

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go to 3

3. ENGINE MECHANICAL PROBLEM
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 the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. O2 SENSOR




1. Ignition on, engine not running.
2. Disconnect the 1/2 O2 Sensor harness connector.
3. With the scan tool, monitor the 1/2 O2 Sensor voltage.
4. The O2 Sensor voltage should read 5.0 volts on the scan tool with the connector disconnected.
5. Using a jumper wire, jump the (K141) O2 Sensor 1/2 Signal circuit to the (K902) O2 Downstream Return circuit in the O2 Sensor harness connector.

NOTE: The voltage should drop from 5.0 volts to 2.5 volts with the jumper wire in place.

Did the O2 Sensor volts change from 5.0 volts to 2.5 volts?

Yes

- Replace the O2 Sensor
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT
1. Remove the jump wire.
2. Ignition on, engine not running.
3. With the scan tool, monitor the 1/2 O2 Sensor voltage.

Is the voltage above 4.8 volts?

Yes

- Go To 6

No

- Check the (K141) O2 Sensor 1/2 Signal circuit for an open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT




1. Turn the ignition off.
2. Measure the resistance between ground and the (K299) O2 Sensor 1/2 Heater Control circuit in the O2 Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair the short to ground in the (K299) O2 Sensor 1/2 Heater Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 7

7. (K902) O2 DOWN STREAM RETURN CIRCUIT




1. Measure the voltage on the (K902) O2 Downstream Return circuit in the O2 Sensor harness connector.

Is the voltage at 2.5 volts?

Yes

- Check the fuel system for contaminants.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Check the (K902) O2 Downstream 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.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test