The following Symptom tables are located in this section:
Important Preliminary Checks Before Starting
Before using this section, perform
Powertrain On Board Diagnostic (OBD) System Check
and verify the following
items:
| • | The powertrain control module (PCM) and malfunction indicator
lamp (MIL) are operating correctly. |
| • | There are no DTCs stored. |
| • | Ensure that the engine coolant temperature is not more than 128°C
(262°F). This condition will cause the PCM to operate in Coolant
Hot mode. While in Coolant Hot mode, the PCM will turn the fuel
OFF to 3 cylinders in order to keep the engine temperatures
from reaching damaging levels. Coolant Hot mode will be perceived
as a lack of power, miss, or rough idle. If the vehicle is operating
in Coolant Hot mode, refer to
Engine Overheating
in Engine Cooling. |
| • | Verify the customer complaint and locate the applicable symptoms.
Perform the procedure included in the Symptom diagnostic table. |
Visual/Physical Checks
Several of the symptom procedures call for a visual/physical inspection.
A careful visual/physical inspection can aid in correcting a problem
without further checks and can save valuable time. A visual/physical
inspection should include the following items:
| • | Verify the PCM grounds are not loose, corroded, or in an improper
location. |
| • | Verify the vacuum hoses are not split, kinked, or improperly
connected. The proper connections are shown on the Vehicle Emission
Control Information label. Check the vacuum hoses for any type
of leak or restriction. Refer to
Emission Hose Routing Diagram
. |
| • | Inspect the air intake ducts for collapsed or damaged areas. |
| • | Check for air leaks at throttle body mounting area, the mass air
flow (MAF) sensor, and the intake manifold sealing surfaces. |
| • | Inspect the ignition wires for cracking, hardness, proper routing,
and carbon tracking. |
| • | Inspect the wiring for improper connections, pinches, and cuts. |
