DTC P0201, P0202, P0203, or P0204. Chevrolet Alero Export 2001

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2001 🢒 Alero Export 🢒 DTC 🢒 DTC P0201, P0202, P0203, or P0204

Circuit Description

The powertrain control module (PCM) enables the appropriate fuel injector on the intake stroke for each cylinder. An ignition voltage is supplied to the fuel injectors. The PCM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The PCM monitors the status of each driver. If the PCM detects an incorrect voltage for the commanded state of the driver, a fuel injector control DTC sets.

Conditions for Running the DTC

•	The engine is running.

•	The ignition voltage is between 9-18 volts.

Conditions for Setting the DTC

•	The PCM detects an incorrect voltage on the fuel injector control circuit.

•	The condition exists for 30 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.

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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 may help 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.

This step tests for voltage at the fuel injector harness connector. The FP-INJR fuse supplies power to the coil side of the fuel injector harness connector. If the fuse is open, a short to ground on the fuel injector ignition voltage circuit is indicated.

This step verifies that the PCM is able to control the fuel injector. If the test lamp blinks, then the PCM and the wiring are OK.

This step tests if a ground is constantly being applied to the fuel injector.

Step	Action	Yes	No
Schematic Reference: Engine Controls Schematics
1	Did you perform the Diagnostic System Check-Engine Controls?	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	With a scan tool clear the DTCs. Idle the engine at the normal operating temperature. With a scan tool, observe the misfire current counters. Are any of the misfire current counters incrementing?	Go to Step 4	Go to Step 3
3	Observe the Freeze Frame and/or Failure records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame and/or Failure records data that you observed. Does the DTC fail this ignition?	Go to Step 4	Go to Diagnostic Aids
4	Turn OFF the ignition. Disconnect the appropriate harness connector of the fuel injector. Turn On the ignition, with the engine OFF. Probe the ignition voltage circuit of the fuel injector with a test lamp connected to a good ground. Command the fuel pump ON with a scan tool. Does the test lamp illuminate when the fuel pump is commanded ON?	Go to Step 5	Go to Step 11
5	Connect the fuel injector test lamp J 34730-405 between the control circuit and the ignition voltage circuit of the fuel injector harness connector. Start the engine. Does the test lamp blink?	Go to Step 9	Go to Step 6
6	Does the test lamp remain illuminated at all times?	Go to Step 8	Go to Step 7
7	Test the control circuit of the fuel injector for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 10
8	Test the control circuit of the fuel injector for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 13
9	Inspect for poor connections at the harness connector of the fuel injector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 12
10	Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 13
11	Repair the ignition voltage circuit of the fuel injector for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 14	--
12	Replace the fuel injector. Refer to Fuel Injector Replacement . Is the action complete?	Go to Step 14	--
13	Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete?	Go to Step 14	--
14	Use the scan tool in order to clear the DTCs. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC run and pass?	Go to Step 15	Go to Step 2
15	With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed?	Go to Diagnostic Trouble Code (DTC) List	System OK