GM Service Manual Online
For 1990-2009 cars only

Object Number: 548554  Size: MF
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM controls the fuel injector control circuit using a Multi Function Driver (MFD). The MFD has the ability to detect an electrical malfunction. If an electrical malfunction is detected, the MFD signals the PCM to set this DTC.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    •  An incorrect voltage level is being detected on the injector driver circuit.
    •  Above condition for over 30 seconds.

Action Taken When the DTC Sets

    • The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
    • The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC

    • The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using a scan tool.

Diagnostic Aids

Monitor the injector fault parameter in the scan tool. Move the electrical harnesses for the effected electrical circuit. If the status changes on the scan tool, that may be an indicator where an intermittent fault may be located.

Inspect for the following:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    • Loose terminal connection
       -  Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
       -  Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
    • Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
    •  Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. If the scan tool indicates STUCK HIGH there is a short to battery positive voltage on the fuel injector control circuit.

  2. If the scan tool indicates STUCK LOW there is an open or a short to ground on the fuel injector control circuit.

  3. If the scan tool indicates a STUCK HIGH while cranking, the short to battery positive voltage is between the injector connector and the PCM. If the scan tool indicates STUCK LOW while cranking the problem is within the injector.

  4. This step is testing for a short to ground in the circuit.

  5. The fuel injector in this circuit will need to be tested after the short to ground is repaired or after the PCM is replaced.

  6. This step is testing the function of the PCM. If the test lamp flashes then the PCM is able to supply the ground.

  7. This step will find a open between the splice and the injector.

  8. This vehicle is equipped with a PCM which utilizes an Electronically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

Fuel Injector Ckt Table 201-206

Step

Action

Values

Yes

No

1

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

Start and idle the engine.

Does scan tool indicate this DTC failed this ignition?

--

Go to Step 4

Go to Step 3

3

Operate the vehicle within Fail Record conditions.

Does scan tool indicate this DTC failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4

  1. Start the engine.
  2. With a scan tool, observe the Cylinder Injector Ckt. Status parameter for this injector.

Does scan tool indicate this parameter STUCK HIGH?

--

Go to Step 6

Go to Step 5

5

Does the scan tool indicate this parameter STUCK LOW?

--

Go to Step 9

Go to Diagnostic Aids

6

  1. Turn OFF the ignition.
  2. Disconnect the fuel injector connector.
  3. With a scan tool, observe the Cylinder Injector Ckt. Status parameter for this injector while cranking the engine.

Does the scan tool indicate this parameter STUCK HIGH when the engine is cranking?

--

Go to Step 7

Go to Step 8

7

Test for a short to voltage on the control circuit for this injector. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

8

Does the scan tool indicate this parameter STUCK LOW while cranking the engine?

--

Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F)

--

9

  1. Disconnect the fuel injector connector.
  2. Probe the control circuit using a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 11

10

Test for a short to ground on this injector control circuit. Refer to Circuit Testing and Wiring Repairs

Did you find and correct the conditions?

--

Go to Step 17

Go to Step 16

11

  1. Leave the test lamp connected.
  2. Crank the engine.

Does the test lamp flash?

--

Go to Step 13

Go to Step 12

12

Test for an open in the injector control circuit. Refer to Testing for Intermittent Conditions and Poor Connections or Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

13

Test for an open or poor connection in the fuel injector feed circuit. Refer to Testing for Intermittent Conditions and Poor Connections or Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

14

Inspect the injector control circuit for a poor connection at the fuel injector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F)

15

Inspect the injector control circuit for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

16

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Did you complete the replacement?

--

Go to Step 17

--

17

  1. Turn ON the ignition, with the engine OFF.
  2. Use the scan tool in order to clear the DTCs.
  3. Operate the vehicle within the Fail Records conditions.

Does the DTC reset?

--

Go to Step 2

System OK