GM Service Manual Online
For 1990-2009 cars only

System Description

The valve lifter oil manifold (VLOM) solenoid for cylinder #1 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P3401 Cylinder 1 Deactivation Solenoid Control Circuit

Conditions for Running the DTC

    • The engine speed is greater than 400 RPM.
    • The ignition voltage is greater than 10 volts, but less than 18 volts.
    • DTC P3401 runs continuously once the above conditions are met.

Conditions for Setting the DTC

    • The ECM detects that the command state of the low-side driver and the actual voltage level of the control circuit do not match.
    • The condition exists for more than 5 seconds.

Action Taken When the DTC Sets

    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the MIL/DTC

    • 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 non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Diagnostic Aids

This diagnostic table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test in Engine Electrical.

Test Description

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

  1. This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.

  2. This step tests for an open circuit to the ENG 1 fuse.

  3. The question in this step is based on the testing that took place in step 4.

  4. This step performs a functional test of the VLOM assembly.

  5. This step tests cylinder #1 VLOM solenoid for a short to ground condition.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

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

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  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 3

Go to Intermittent Conditions

3

  1. Turn OFF the ignition.
  2. Probe both test points of the ENG 1 fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp illuminate on either test point of the ENG 1 fuse?

--

Go to Step 18

Go to Step 4

4

  1. Turn ON the ignition, with the engine OFF.
  2. Probe both test points of the ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp illuminate on both test points of the fuse?

--

Go to Step 6

Go to Step 5

5

Does the test lamp illuminate on one test point of the fuse?

--

Go to Step 22

Go to Powertrain Relay Diagnosis

6

  1. Turn ON the ignition, with the engine OFF.
  2. Connect the scan tool to the diagnostic link connector (DLC).
  3. Listen for a clicking sound coming from the valve lifter oil manifold (VLOM) assembly area.
  4. Command the solenoid for cylinder #1 ON and OFF several times with a scan tool.

Does the solenoid click each time when commanded ON and OFF with the scan tool?

--

Go to Intermittent Conditions

Go to Step 7

7

  1. Disconnect the VLOM assembly electrical connector.
  2. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Connect the cable labeled Resistance from the Displacement on Demand (DoD) tester to the electrical connector on the VLOM assembly.
  3. Connect both the positive and the negative power leads of the DoD tester to the respective battery terminals at the battery.
  4. Connect the leads of the DMM to the resistance test ports on the DoD tester.
  5. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.
  6. Zero the DMM display.
  7. Monitor the DMM display.
  8. Press and hold the switch pad marked solenoid #1 on the DoD tester.

Does the resistance measure within the specified value?

11-18 ohms

Go to Step 9

Go to Step 40

9

  1. Turn OFF the ignition.
  2. Connect the cable labeled Power from the Displacement on Demand (DoD) tester to the electrical connector on the VLOM assembly.
  3. Listen for a clicking sound coming from the VLOM assembly area on the engine.
  4. Command the solenoid for cylinder #1 ON and OFF several times using the DoD tester.

Does the solenoid click each time when commanded ON and OFF with the DoD tester?

--

Go to Step 10

Go to Displacement on Demand (DoD) Valve Lifter Oil Manifold Diagnosis and Testing

10

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit wire terminal at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 14

11

  1. Turn OFF the ignition.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 26

Go to Step 12

12

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 30

Go to Step 13

13

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.
  3. Command the solenoid for cylinder #1 ON with a scan tool.

Does the test lamp illuminate?

--

Go to Intermittent Conditions

Go to Step 16

14

  1. Turn OFF the ignition.
  2. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
  4. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 15

15

  1. Turn OFF the ignition.
  2. Measure the resistance of the ignition 1 voltage circuit from the VLOM wire harness electrical connector to the underhood fuse block wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems.

Does the resistance measure greater than the specified value?

2ohms

Go to Step 32

Go to Step 39

16

  1. Turn OFF the ignition.
  2. Disconnect the engine control module (ECM) electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
  3. Test for shorted terminals and poor connectors at the ECM electrical connector and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 17

17

  1. Turn OFF the ignition.
  2. Measure the resistance of the solenoid control circuit for the cylinder #1 from the VLOM wire harness electrical connector to the ECM wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems.

Does the resistance measure greater than the specified value?

2ohms

Go to Step 33

Go to Step 41

18

  1. Turn OFF the ignition.
  2. Disconnect the VLOM assembly electrical connector.
  3. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 19

19

  1. Turn OFF the ignition.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 28

Go to Step 20

20

  1. Turn OFF the ignition.
  2. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
  4. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 21

21

  1. Turn OFF the ignition.
  2. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors in Wiring Systems.
  3. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly.
  4. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  5. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 34

Go to Step 39

22

  1. Turn OFF the ignition.
  2. Disconnect the VLOM assembly electrical connector.
  3. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 23

23

  1. Turn OFF the ignition.
  2. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
  4. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 24

24

  1. Turn OFF the ignition.
  2. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors in Wiring Systems.
  3. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly.
  4. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  5. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 35

Go to Step 25

25

  1. Turn OFF the ignition.
  2. Connect the cable labeled RESISTANCE from the DoD tester to the electrical connector on the VLOM assembly.
  3. Connect both the positive and the negative power leads of the DoD tester to the respective battery terminals at the battery.
  4. Connect one lead of the DMM to a resistance test port on the DoD tester.
  5. Connect the other DMM lead to a good ground on the engine.
  6. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems.
  7. Zero the DMM display.
  8. Monitor the DMM display.
  9. Press and hold the switch pad marked Solenoid #1 on the DoD tester.

Does the DMM display OL?

--

Go to Step 39

Go to Step 40

26

  1. Turn OFF the ignition.
  2. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
  3. Test for shorted terminals and poor connections at the ECM electrical connector, and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 27

27

  1. Turn OFF the ignition.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 36

Go to Step 41

28

  1. Turn OFF the ignition.
  2. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
  3. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 29

29

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 37

Go to Step 41

30

  1. Turn OFF the ignition.
  2. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
  3. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 42

Go to Step 31

31

  1. Turn OFF the ignition.
  2. Disconnect the solenoid control circuit wire terminal for cylinder #1 from the ECM wire harness electrical connector. Refer to Tyco/AMP Connectors in Wiring Systems.
  3. Connect the ECM wire harness electrical connector to the ECM.
  4. Turn ON the ignition, with the engine OFF.
  5. Probe the solenoid control circuit wire terminal for cylinder #1 at the ECM electrical connector with a test lamp that is connected to a good ground. . Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 38

Go to Step 41

32

Repair the high resistance or an open in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

33

Repair the high resistance or an open in the solenoid control circuit for cylinder #1 between the ECM wire harness electrical connector and the VLOM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

34

Repair the short to battery positive in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

35

Repair the short to ground in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

36

Repair the short to ground in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

37

Repair the short to battery positive voltage in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

38

Repair the short to ignition 1 voltage in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 42

--

39

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the replacement?

--

Go to Step 42

--

40

Replace the VLOM assembly. Refer to Valve Lifter Oil Manifold Replacement in Engine Mechanical.

Did you complete the replacement?

--

Go to Step 42

--

41

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 42

--

42

  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 43

43

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK