Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- Diagnose all other DTCs before continuing.NOTE:
Check for contaminants that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
- Start the engine.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read 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?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION . .
- Diagnose all other DTCs before continuing.
- CHECK THE FUEL DELIVERY SYSTEM
- Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START)
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 3
- Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START)
.
- CHECK THE EXHAUST SYSTEM FOR LEAKS
- Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 4
- Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS
.
- CHECK THE OXYGEN SENSOR OPERATION
- Perform the CHECKING THE OXYGEN SENSOR OPERATION test procedure. Refer to CHECKING THE OXYGEN SENSOR OPERATION
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 5
- Perform the CHECKING THE OXYGEN SENSOR OPERATION test procedure. Refer to CHECKING THE OXYGEN SENSOR OPERATION
.
- O2 SENSOR 2/1 HEATER OPERATION
- Turn the ignition off.NOTE:
Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 volts.
- Turn the ignition on.
- With the scan tool, actuate the O2 Sensor 2/1 Heater Test.
- With the scan tool, monitor O2 Sensor 2/1 voltage for at least two minutes.
Does the voltage stay above 4.5 volts?
Yes
- Verify that there is good pin to terminal contact in the O2 Sensor 2/1 and Powertrain Control Module connectors. Replace the O2 Sensor 2/1 if no problems were found with the connectors. Refer to OXYGEN SENSOR, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 6
- Turn the ignition off.
- CHECK THE MAP SENSOR OPERATION
- Perform the CHECKING THE MAP SENSOR OPERATION test procedure. Refer to CHECKING THE MAP SENSOR OPERATION
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 7
- Perform the CHECKING THE MAP SENSOR OPERATION test procedure. Refer to CHECKING THE MAP SENSOR OPERATION
.
- CHECK THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION
- Perform the CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION test procedure. Refer to CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 8
- Perform the CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION test procedure. Refer to CHECKING THE ENGINE COOLANT TEMPERATURE SENSOR OPERATION
.
- EVAP PURGE SOLENOID OPERATION
- Turn the ignition off.
- Disconnect the hoses at the Evap Purge Solenoid.
- Using a hand vacuum pump, apply 1.0 in. Hg. to the "ENGINE" side of the Evap Purge Solenoid.NOTE:
The solenoid should hold vacuum for a minimum of 15 seconds.
Did the Evap Purge Solenoid hold vacuum?
Yes
- Go To 9
No
- Verify that there is good pin to terminal contact in the Evap Purge Solenoid and Powertrain Control Module connectors. Replace the Evap Purge Solenoid if no problems were found with the connectors. Refer to SOLENOID, EVAPORATIVE EMISSIONS PURGE, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST
.
.NOTE:
Connect the vacuum hoses before continuing.
- ENGINE MECHANICAL
- Turn the ignition off.
- 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. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Go To 10
- CHECK RELATED PCM AND COMPONENT CONNECTIONS
- Perform any Service Bulletins that apply.
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
- Proper connector installation.
- Damaged connector locks.
- Corrosion.
- Other signs of water intrusion.
- Weather seal damage (if equipped).
- Bent terminals.
- Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
- Terminals that have been pushed back into the connector cavity.
- Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
- Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace the Powertrain Control Module in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
No
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST . .
- Test complete.