GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Chevy C Silverado - 2WD (CNG) 🢒 DTC 🢒 DTC P0200

Circuit Description

The PCM controls fuel delivery and determines fuel system operation on Bi-fuel (KL6) vehicles. The PCM is not capable of operating the high current CNG fuel injectors. The PCM injector control signals are received by the fuel injector control module (FICM) and duplicate control signals are generated by the FICM in order to operate the CNG injectors. On Bi-fuel equipped vehicles, the FICM switches off the CNG fuel injectors and re-routes the injector control signals from the PCM to the gasoline fuel injectors. A fused ignition voltage is supplied to all of the fuel injectors. The PCM monitors the status of each injector control circuit. DTC P0200 will set if there is condition on a control circuit between the PCM and FICM. On Bi-fuel (KL6) vehicles, DTC P0200 can set during gasoline operation, if a circuit condition is detected between the AF injector relay and a gasoline fuel injector.

Conditions for Running the DTC
    • The engine speed is more than 400 RPM.
    • The ignition voltage is between 6 and 18 volts.

Conditions for Setting the DTC
    • The powertrain control module (PCM) detects an incorrect voltage on a fuel injector control circuit.
    • The condition exists for 5 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
    • Performing the Fuel Injector Coil Test on the gasoline fuel injectors may help to isolate an intermittent condition. Refer to Fuel Injector Solenoid Coil Test .
    • For an intermittent condition, refer to Intermittent Conditions .

Test Description

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

  1. This step verifies that a condition exists.

    2.

  2. The step determines if the condition occurs during gasoline operation. If the vehicle misfires while on gasoline, then the condition is between the FICM and the gasoline fuel injector.

    3.

  3. This step tests the control circuit between the PCM and the FICM. The test lamp should blink while the engine is cranking. The AF fuel mode relay must be removed in order to prevent a fuel system switch-over.

    4.

  4. This step tests the injector control circuit between the AF injector relay and the PCM. The test lamp should blink while the engine is cranking.

    5.

  5. This step verifies that an ignition voltage is supplied to the gasoline fuel injector. If the ignition voltage circuit is open DTC P0200 will set while operating on gasoline.

    6.

  6. This step tests the injector control circuit between the gasoline fuel injector and the AF injector relay. The test lamp should blink while the engine is running.

    7.

  7. This step tests the ignition voltage circuit to the AF injector relay. If the relay does not switch during gasoline operation, DTC P0200 will set.

    8.

  8. This step tests the ground circuit to the AF injector relay. If the relay does not switch during gasoline operation, DTC P0200 will set.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Fuel Injector Control Module Connector End Views

1

Did you perform the Diagnostic System Check Alternative Fuels - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Alternative Fuels (Engine Controls)

2
  1. Clear the DTCs with a scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Monitor the misfire current counters with a scan tool.

Are any of the misfire current counters incrementing?

Go to Step 6

Go to Step 3

3

Is this vehicle equipped with the Bi-fuel option (KL6)?

Go to Step 4

Go to Step 5

4

Important: Verify that the gasoline fuel level is above 10% in order to prevent misdiagnosis. The misfire counters may not increment if the gasoline fuel level is below 10%.

  1. Force a fuel system switch-over to gasoline with the scan tool.
  2. Monitor the misfire current counters with a scan tool.

Are any of the misfire current counters incrementing?

Go to Step 13

Go to Step 5

5
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 6

Go to Diagnostic Aids

6
  1. Turn OFF the ignition.
  2. Remove the AF fuel mode relay.
  3. Disconnect the harness connector of the FICM.
  4. Probe the injector control circuit from the PCM, which displays the highest number of misfire current counters, with a test lamp connected to B+.
  5. Crank the engine, while observing the test lamp.

Does the test lamp blink?

Go to Step 21

Go to Step 7

7

Does the test lamp remain illuminated?

Go to Step 12

Go to Step 8

8

Is this vehicle equipped with the Bi-fuel option (KL6)?

Go to Step 9

Go to Step 11

9
  1. Turn OFF the ignition.
  2. Disconnect the appropriate AF injector relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the fuel injector control circuit from the PCM, with a test lamp connected to B+.
  5. Crank the engine, while observing the test lamp.

Does the test lamp blink?

Go to Step 10

Go to Step 11

10

Test the control circuit of the fuel injector for an open, or a short to voltage between the relay and the fuel injector.

Did you find and correct the condition?

Go to Step 31

Go to Step 20

11

Test the control circuit of the fuel injector for an open, or a short to voltage between the following:

    • PCM and the FICM (KL8)
    • PCM and the AF injector relay (KL6)

Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 22

12

Test the fuel injector control circuit for a short to ground between the following:

    • PCM and the FICM (KL8)
    • PCM and the AF injector relay (KL6)
    • AF injector relay and FICM (KL6)
    • AF injector relay and the gasoline fuel injector (KL6)

Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 30

13
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the gasoline fuel injector which displays the highest level of misfire.
  3. Probe the ignition voltage circuit of the gasoline fuel injector with a test lamp connected to a good ground.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 14

Go to Step 24

14
  1. Probe the control circuit of the gasoline fuel injector with a test lamp connected to B+.
  2. Start and idle the engine.
  3. Force a fuel system switch-over to gasoline with the scan tool.
  4. Observe the test lamp.

Does the test lamp blink?

Go to Step 19

Go to Step 15

15

Does the test lamp remain illuminated?

Go to Step 23

Go to Step 16

16
  1. Turn OFF the ignition.
  2. Remove the appropriate AF injector relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition positive circuit of the AF relay coil with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 17

Go to Step 25

17
  1. Probe the ground circuit of the AF injector relay coil with a test lamp connected to B+.
  2. Start and idle the engine.
  3. Force a fuel system switch-over to gasoline with the scan tool.

Does the test lamp illuminate?

Go to Step 18

Go to Step 26

18

Test the control circuit of the fuel injector for an open, or a short to voltage between the gasoline fuel injector and the relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 20

19

Test for an intermittent and for a poor connection at the gasoline fuel injector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 28

20

Test for an intermittent and for a poor connection at the AF injector relay. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 27

21

Test for an intermittent and for a poor connection at the FICM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 29

22

Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 31

Go to Step 30

23

Repair the short to ground on the control circuit of the gasoline fuel injector, between the injector and the AF injector relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 31

--

24

Important: The fuse also supplies voltage to the ignition coil modules. If the fuse is open, inspect all related circuits and components for a short to ground. Refer to Circuit Testing in Wiring Systems.

Repair the ignition 1 voltage circuit of the fuel injector for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 31

--

25

Repair the ignition 1 voltage circuit of the AF injector relay coil for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 31

--

26

Repair the ground circuit of the AF injector relay coil for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 31

--

27

Replace the AF injector relay.

Did you complete the replacement?

Go to Step 31

--

28

Replace the gasoline fuel injector. Refer to Fuel Injector Replacement in the C/K Pickup Service Manual.

Did you complete the replacement?

Go to Step 31

--

29

Replace the FICM. Refer to Fuel Injector Control Module Replacement .

Did you complete the replacement?

Go to Step 31

--

30

Replace the PCM. Refer to Powertrain Control Module Replacement in the C/K Pickup Service Manual.

Did you complete the replacement?

Go to Step 31

--

31
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 32

32

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK