GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.5L (LBK) 🢒 Diagnostic System Check - Engine Controls

Description

The Diagnostic System Check-Engine Controls is an organized approach to identifying a condition that is created by a malfunction in the engine control system. The Diagnostic System Check must be the starting point for any driveability concern. The Diagnostic System Check directs the service technician to the next logical step in order to diagnose the concern. Understanding and correctly using the diagnostic table reduces diagnostic time and prevents the replacement of good parts.

Step

Action

Yes

No

1

Perform the following preliminary inspections:

    • Ensure that the battery is fully charged. Refer to Battery Inspection/Test in Engine Electrical.
    •  Ensure that the battery cables are clean and tight.
    •  Inspect the easily accessible systems or the visible system components for obvious damage or conditions that could cause the symptom.
    •  Ensure that the engine and control module grounds are clean, tight, and in the correct location.
    •  Inspect for aftermarket devices that could affect the operation of the system. Refer to Checking Aftermarket Accessories in Wiring Systems.

Did you find and correct the condition?

System OK

Go to Step 2

2

  1. Install a scan tool.
  2. Turn ON the scan tool.

Does the scan tool turn ON?

Go to Step 3

Go to Scan Tool Does Not Power Up in Data Link Communications

3

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the Engine control module (ECM).

Does the scan tool communicate with the ECM?

Go to Step 4

Go to Scan Tool Does Not Communicate with Component in Data Link Communications

4

Attempt to start the engine.

Does the engine crank?

Go to Step 5

Go to Symptoms - Engine Electrical in Engine Electrical

5

Did the engine start and idle?

Go to Step 6

Go to Engine Cranks But Does Not Run

6

Important: Do NOT clear the DTCs unless instructed by a diagnostic procedure.

  1. Select the DTC display function for the engine control module and record the DTCs.
  2. If multiple powertrain DTCs are stored, diagnose the DTCs in the following order:
    3. 2.1. Test for component level DTCs. For example, sensor DTCs, solenoid DTCs, and relay DTCs

    Begin with the lowest number DTC unless the diagnostic table directs you otherwise.

    2.2. Test for system level DTCs. For example, misfire DTCs, EVAP system DTCs and fuel trim DTCs.
  3. If there are any powertrain DTCs, Select Capture Info in order to store the Powertrain DTC information with a scan tool.

Does the scan tool display any DTCs?

Go to Step 7

Go to Step 10

7

Does the scan tool display DTCs P1670, P1671, P1672, P1673 or UXXXX?

Go to Scan Tool Does Not Communicate with Component in Data Link Communications

Go to Step 8

8

Does the scan tool display DTCs P0601, P0604, P0605, or P1615?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 9

9

Does the scan tool display DTCs P0562, or P0563?

Go to DTC P0562 or DTC P0563 in Engine Electrical

Go to Diagnostic Trouble Code (DTC) List

10

Are there any TCM DTCs or any automatic transmission symptoms?

Go to Diagnostic System Check - Automatic Transmission in Automatic Transmission - Aisin ZF 4HP 16

Go to Step 11

11

Are there any engine controls or driveability symptoms observed?

Go to Symptoms - Engine Controls

System OK