Chevrolet Cobalt Service & Repair Manual: EGR Functional Tests
Fuel Injected Gasoline Engine
| The EGR systems used on fuel injected
engines are controlled by the ECM. The ECM will store a code in memory when
the EGR system malfunctions. Refer to appropriate "Diagnostic Code Identification
Chart" for code number. |
Linear EGR Valve
| 1. |
Connect Tech 1 Scan Tool, or equivalent,
to DLC following tool manufacturer's instructions. |
| 2. |
Correct any DTCs that may be present,
particularly those pertaining to MAP sensor fault conditions. |
| 3. |
Start engine and operate at approximately
1500 RPM, then select MISCELLANEOUS TEST, EGR CONTROL with scan
tool. |
| 4. |
EGR valve should cycle through 25%
through 100% positions. |
| 5. |
Engine RPM should drop and idle should
roughen as EGR valve is cycled. |
|
PCM & ECM Controlled EGR Valve
| This EGR system is controlled
by ECM or PCM, which will store a code in memory when EGR system is faulty. |
Gasoline & Alternative Fuel Engine Vehicles
Visual Inspection
To ensure proper operation of
all emission control system components it is required to perform a visual
inspection. R ...
Change Oil, Change Oil Now Or Change Oil Soon Messages
After changing the engine oil,
the system must be reset as follows:
1.
Turn ignition to RUN with en ...
Chevrolet Cobalt Owners Manual
Chevrolet Cobalt Service Manual
Vehicle Visual Inspection Procedures
Emission Control Service Reminder Indicators (SRI) Reset Procedures