GM Service Manual Online
For 1990-2009 cars only

Object Number: 185026  Size: LF
Engine Controls Components
Fuel Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The injection pump fuel supply line has a solenoid controlled shutoff located in the injection pump. When the solenoid is energized (key in the run position), the valve is open and fuel is supplied to the injection pump. By providing a ground path, the PCM energizes the solenoid.

Conditions for Running the DTC

The ignition switch in the ON position or the engine is operating.

Conditions for Setting the DTC

    • The PCM has requested the ESO ON and the control circuit voltage at the PCM is more than 8 volts.
    • All of the diagnostic set conditions met for 2 seconds.

or

    • The PCM has requested the ESO OFF and the control circuit voltage at the PCM is less than 8 volts.
    • All of the diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets

    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM records the operating conditions at the time the diagnostic fails. This information will store in the Failure Records.

Conditions for Clearing the MIL/DTC

    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures
    • The use of a scan tool.

Diagnostic Aids

An open in the control circuit or the ignition feed circuit will cause a P0215. Also a no start condition will exist. The scan tool has the ability to turn the engine shutoff solenoid ON and OFF. This can be used as a quick operational check.

An intermittent may be caused by any of the following conditions:

    • A poor connection
    • Rubbed through wire insulation
    • A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step will check the ESO control circuit for an open.

  2. After repairing the circuit for a short to voltage, check the solenoid for proper operation.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The control module's data is deleted once the Clear Info function is used.

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

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn the ignition OFF.
  2. Disconnect the ESO harness electrical connector.
  3. Ignition ON, engine OFF.
  4. With an J 35616-200 unpowered test lamp connected to chassis ground, probe the ESO ignition feed circuit at the engine harness connector.

Is the test light ON?

--

Go to Step 3

Go to Step 6

3

  1. Turn the ignition OFF.
  2. With an J 35616-200 unpowered test lamp, jumper the ESO engine harness terminals together.
  3. Turn the ignition ON leaving the engine OFF.

Is the test light ON?

--

Go to Step 4

Go to Step 7

4

  1. Turn the ignition ON leaving the engine OFF.
  2. With an J 35616-200 unpowered test lamp connected to B+, probe the ESO control circuit.
  3. With the scan tool, command the ESO solenoid ON and OFF.

Does the test light turn ON and OFF with each command?

--

Go to Step 5

Go to Step 8

5

Check the ESO harness for a proper connection and replace the terminals if necessary. Refer to Wiring Repairs in Wiring Systems.

Did any terminal require replacement?

--

Go to Step 13

Go to Step 11

6

  1. Check the ESO ignition feed circuit for the following conditions:
  2. • An open wire
    • An open fuse
  3. Repair the problem as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 13

--

7

  1. Turn the ignition ON leaving the engine OFF.
  2. With an J 35616-200 unpowered test lamp connected to ground, probe the ESO control circuit at the ESO harness connector.

Is the test light ON?

--

Go to Step 10

Go to Step 9

8

Repair the short to ground on the ESO control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 13

--

9

  1. Check the ESO control circuit for the following conditions:
  2. • An open wire
    • Proper connection at the PCM
  3. If an ESO control circuit problem was found, repair it as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 13

Go to Step 12

10

  1. Check the ESO control circuit for a short to voltage.
  2. If an ESO control circuit problem was found, repair it as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 13

Go to Step 12

11

Important: The new injection pump must be timed. Refer to Fuel Injection Pump Timing Adjustment .

Replace the injection pump. Refer to Fuel Injection Pump Replacement .

Is the action complete?

--

Go to Step 13

--

12

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 13

--

13

  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the engine reaches normal operating temperature.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number which was set.
  6. Operate the vehicle, with the Conditions for Setting this DTC, until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

--

Go to Step 14

Go to Step 2

14

Does the scan tool display any additional undiagnosed DTCs?

--

Go to the Applicable DTC Table

System OK