GM Service Manual Online
For 1990-2009 cars only

Dieseling, Run-On Symptom

Step

Action

Value(s)

Yes

No

DEFINITION The engine continues to run after the key is turned off, but runs very rough. If the engine runs smooth, check the ignition switch and the adjustment.

1

Did you perform the On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

2

  1. Perform a bulletin search.
  2. If a bulletin that addresses the symptom is present, correct the condition as instructed in the bulletin.

Did you find a bulletin that addresses the symptom?

--

Go to Step 6

Go to Step 3

3

Did you perform a visual/physical check?

--

Go to Step 4

Go to Symptoms for the Visual /Physical Check

4

  1. Check for a short between B+ and any of the ignition feed circuits. Refer to Fuse and Relay Block Diagnosis or Wiring Repairs in Wiring Systems.
  2. If a problem is present, repair as necessary.

Did you find a problem?

--

Go to Step 7

Go to Step 5

5

  1. Check for the following conditions:
  2. • Fuel in the fuel pressure regulator vacuum hose. If fuel is present in the hose, replace the fuel pressure regulator assembly. Refer to Fuel Pressure Regulator Replacement.
    • Leaking injectors. Refer to Fuel System Diagnosis .
  3. If a problem is present, repair as necessary.

Did you find a problem?

--

Go to Step 7

Go to Step 6

6

  1. Review all of the diagnostic procedures within this table.
  2. If all of the procedures have been completed and no malfunctions have been found, review/inspect the following:
  3. • The scan tool data
    • The Freeze Frame data
    • All of the electrical connections within a suspected circuit and/or system.
  4. If a problem is present, repair as necessary.

Did you find a problem?

--

Go to Step 7

Go to Step 3

7

Operate the vehicle under the same conditions (as closely as possible) as when the original symptom occurred.

Is the original symptom still present?

--

Go to Step 3

Go to Step 8

8

Are other driveability symptoms still present?

--

Go to Symptoms

System OK