Initial Inspection and Diagnostic Overview

PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE

For a complete wiring diagram REFER to DIAGRAMS/ELECTRICAL .


Diagnostic Test


1. NO RESPONSE
NOTE: For vehicle communication problems, use the scan tool to refer to the Network Review Screen. The screen depicts a high level view of the vehicle network. Fault and problem areas appear in red.

Does the scan tool display a Vehicle Network problem or NO RESPONSE condition?

Yes


- Refer to the appropriate BUS Communication test.


No


- Go to 2


2. NO START
Does the vehicle have a NO START condition?

Yes


- Check the vehicle for any DTC(s), including Vehicle Theft Security related DTC(s), that may cause a no-start condition.
- If no DTC(s) are present that relate to a no-start condition, refer to the Non DTC Diagnostic Procedures that relate to Fuel and Starting.


No


- Go to 3


3. VEHICLE REPAIR HISTORY AND TSB(s)
Check the vehicle repair history for repairs that may relate to the current condition.
Inspect the vehicle for aftermarket accessories that may have been installed incorrectly.
Check for any TSB(s) related to the condition or DTC(s).
If a TSB applies, follow the procedure outlined in the TSB.
Select the appropriate response for the condition that applies:

Performing a TSB procedure repaired the condition.


- Test Complete.
- Perform the PCM Verification Test.Powertrain Verification Test


A DTC is present, no TSB applies, or the TSB didn't repair the condition.


- Go to 4


No DTC(s) or other conditions are present.


- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC


4. VEHICLE INSPECTION

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Based on the diagnostic condition that applies, review the following list and perform any tests that relate to the condition:
If multiple DTCs are set in the PCM, review the wiring schematics for problems in any shared supply or ground circuits. Refer to the diagnostic procedure for Checking the PCM Power and Ground Circuits. Checking the PCM Power and Ground Circuits
Inspect the air intake system and, if equipped, any turbocharger related tubes for damage, restriction, or poor connection.
Inspect the exhaust system and related tubes for damage, restriction, or poor connection.
Remove and inspect the Air Filter for excessive dirt and debris which may cause an air flow restriction.
When the PCM detects and stores a DTC, the PCM also stores the environmental conditions under which the DTC was set.
Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
With the scan tool, clear the stored DTC(s).
Attempt to duplicate the environmental conditions under which the DTC was set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the vehicle conditions under which the DTC conditions will be monitored. Operate the vehicle under those conditions.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the component and the module.
If the DTC(s) are fuel or air related, check the fuel level and quality.
Were any repairs made that corrected the DTC or condition?

Yes


- Test complete.
- Perform the PCM Verification Test.Powertrain Verification Test


No


- Diagnose and repair the DTC(s).