2000 - 2999: 2092
2092-FUEL SYSTEM LEAN - BANK 1
For a complete wiring diagram Consult Diagrams/Electrical.
Theory of Operation
The fuel feedback system will maintain a stoiciometric fuel/air mixture, 14.7:1, by modifying the injector pulse width according to the oxygen content of the exhaust gas. The PCM makes short term and long term fuel corrections to maintain stoiciometric fuel/air ratio for best catalytic converter efficiency. Short term fuel correction is based on upstream O2 sensor output and is designed for quick engine response. The long term fuel correction compensated for variations in the engine specifications, sensor tolerances and component aging and is designed to correct rich and lean conditions over a longer period of time.
- When Monitored:
With the engine running in closed loop mode, the ambient/battery temperature above -6.7° C (20° F) and altitude below 2590.8 m (8500 ft).
- Set Condition:
If the PCM multiplies short term compensation by long term adaptive and 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. Initial Inspection and Diagnostic Overview.
Diagnostic Test
1. ACTIVE DTC
NOTE: Check for contaminates that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
Start the engine.
Allow the engine to reach normal operating temperature.
With a scan tool, select View DTCs.
NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
Is the DTC Active or Pending at this time?
Yes
- Go To 2
No
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
2. CHECKING FUEL PRESSURE
WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in personal injury or death.
Install a fuel pressure gauge to the fuel rail.
Ignition on, engine not running.
With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge.
NOTE: Fuel pressure specification is 407 kPa +/- 34 kPa (59 psi +/- 5 psi).
Turn the ignition off.
Choose a conclusion that best matches your fuel pressure reading.
Within Specification
- Go To 3
Above Specification
- Replace the fuel filter/pressure regulator.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
CAUTION: Stop All Actuations.
3. MAP SENSOR OPERATION
Ignition on, engine not running.
With a scan tool, read the Barometric Pressure.
NOTE: The Barometric Pressure should be approximately equal to the actual barometric pressure. If necessary, compare the Barometric Pressure value of this vehicle to the value of a known good vehicle of a similar make and model.
Turn the ignition off.
Connect a Vacuum Gauge to a Manifold Vacuum source.
Start the engine.
Allow the engine to idle.
NOTE: If engine will not idle, maintain a constant RPM above idle.
With a scan tool, read the MAP Sensor vacuum value.
Is the scan tool reading for MAP Vacuum within 1 inch of Hg on the Vacuum Gauge reading and is the Barometric Pressure reading of the vehicle the approximately the same as actual Barometric Pressure?
Yes
- Go To 4
No
- Replace the MAP Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NOTE: Remove the vacuum gauge before continuing.
4. ECT SENSOR OPERATION
NOTE: For this test to be valid, the thermostat must be operating correctly.
NOTE: This test works best if performed on a cold engine (cold soak)
Ignition on, engine not running.
With a scan tool, read the Engine Coolant Temperature Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature.
NOTE: If engine coolant temperature is above 82° C (180° F), allow the engine to cool until 65° C (150° F) is reached.
Start the Engine.
During engine warm-up, monitor the Engine Coolant Temperature value. The temp value change should be a smooth transition from start up to normal operating temp 82° C (180° F). The value should reach at least 82° C (180° F).
Did the ECT value increase smoothly and reach at least 82° C (180° F)?
Yes
- Go To 5
No
- Replace the Engine Coolant Temperature Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
5. EVAP PURGE SOLENOID OPERATION
Turn the ignition off.
Disconnect the hoses at the Evap Purge Solenoid.
Using a hand vacuum pump, apply 10 inches of vacuum to the Evap Purge Solenoid vacuum source port on the component side.
Did the Evap Purge Solenoid hold vacuum?
Yes
- Go To 6
No
- Replace the EVAP Purge Solenoid.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NOTE: Connect the vacuum hoses before continuing.
6. ENGINE MECHANICAL
Check for any of the following conditions/mechanical problems.
AIR INDUCTION SYSTEM - must be free from restrictions.
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 7
7. 02 1/1 HEATER CONTROL SUPPLY CIRCUIT OPEN
Disconnect the Oxygen sensor harness connector.
Remove the Engine control relay.
NOTE: Check connectors - Clean/repair as necessary, inspect for signs of Water intrusion in the connector.
Measure the resistance of the 02 1/1 HEATER CONTROL SUPPLY circuit between the O2 sensor harness connector and the Engine control relay connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 8
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
8. 02 1/1 HEATER CONTROL RETURN CIRCUIT OPEN
Measure the resistance of the 02 1/1 HEATER CONTROL RETURN circuit between the O2 sensor harness connector and the C2 PCM harness connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 9
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
9. 02 1/1 PUMP CURRENT CIRCUIT OPEN
Measure the resistance of the 02 1/1 pump current circuit between the O2 sensor harness connector and the C2 PCM harness connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 10
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
10. 02 1/1 RETURN CIRCUIT OPEN
Measure the resistance of the 02 1/1 return circuit between the O2 sensor harness connector and the C2 PCM harness connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 11
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
11. 02 1/1 PUMP CELL CURRENT TRIM CIRCUIT OPEN
Measure the resistance of the 02 1/1 pump cell current trim circuit between the O2 sensor harness connector and the C2 PCM harness connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 12
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
12. 02 1/1 SIGNAL CIRCUIT OPEN
Measure the resistance of the 02 1/1 signal circuit between the O2 sensor harness connector and the C2 PCM harness connector.
Is the resistance less than 10 Ohms?
Yes
- Go To 13
No
- Replace or repair the Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
13. OXYGEN SENSOR
Measure resistance of the 02 sensor heater between the 02 HEATER CONTROL SUPPLY and 02 HEATER CONTROL RETURN circuits at the O2 sensor.
Is the resistance 3.2 +/- 0.8 ohms at ambient temperature?
Yes
- Replace the PCM.
- Replace and program the Powertrain Control Module Testing and Inspection
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Replace the sensor
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test