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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 DTC 🢒 DTC P0562

DTC P0562 w/2.0L L34 GMDAT

Circuit Description

The engine control module (ECM) uses the ignition 1 voltage circuit to monitor system voltage. Voltage that is out of range will cause damage to components and incorrect input readings. If the ECM detects an excessively low system voltage, DTC P0562 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0562 System Voltage Low

Conditions for Running the DTC
    • The ignition is ON with the engine OFF.
    • DTC P0562 runs continuously once the above condition is met.

Conditions for Setting the DTC

The ECM detects a system voltage below 11 volts for more than 5 minutes.

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 not 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 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.

Step

Action

Value

Yes

No

Schematic References: Engine Controls Schematics in Engine Controls - 2.0L (L34), or Engine Controls Schematics in Engine Controls - 2.5L (LBK)

Connector End View References: Engine Controls Connector End Views in Engine Controls - 2.0L (L34), Engine Controls Connector End Views in Engine Controls - 2.5L (LBK), Engine Control Module Connector End Views in Engine Controls - 2.0L (L34) or Engine Control Module Connector End Views in Engine Controls - 2.5L (LBK)

1

Did you perform the Diagnostic System Check - Engine Electrical?

--

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2
  1. Start the engine.
  2. Raise the engine speed above 1,500 RPM.
  3. With a scan tool, observe the Ignition 1 voltage parameter in the engine control module (ECM) data list.

Is the voltage more than the specified value?

10.5 V

Go to Step 3

Go to Step 4

3
  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. 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 4

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

4
  1. Measure the voltage at the battery with a DMM.
  2. Raise the engine speed above 1,500 RPM.
  3. Compare the voltage at the battery to the Ignition 1 voltage parameter in the ECM data list.

Is the battery voltage and Ignition 1 parameter readings different by more than the specified value?

0.5 V

Go to Step 5

Go to Charging System Test

5

Test the ignition 1 voltage circuit of the ECM for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 6

6

Test for an intermittent or poor connection at the harness connector of the ECM. 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 8

Go to Step 7

7

Replace the ECM. Refer the appropriate procedure:

    •  Engine Control Module Replacement in Engine Controls - 2.0L (L34)
    •  Engine Control Module Replacement in Engine Controls - 2.5L (LBK)

Did you complete the replacement?

--

Go to Step 8

--

8
  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 9

9

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.0L (L34) Diagnostic Trouble Code (DTC) List in Engine Controls - 2.5L (LBK)

System OK

DTC P0562 w/2.5L LBK

Circuit Description

The engine control module (ECM) monitors the voltage supplied on the feedback circuit of the engine controls ignition relay or ENG MAIN relay. Voltage that is out of range will cause incorrect input readings from the engine components connected to the relay. If the ECM detects low voltage on the feedback circuit of the engine ENG MAIN relay, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0562 Engine Controls Ignition Relay Feedback Circuit

Conditions for Running the DTC
    • The ignition is ON or the engine is running.
    • DTC P0562 runs continuously once the above condition is met.

Conditions for Setting the DTC

The ECM detects voltage below 7.9 volts or more than 26 volts for more than 10 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 not 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 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
    • For an intermittent condition, refer to Intermittent Conditions .
    • The following table illustrates the ENG Main relay terminal location in the underhood fuse block:

ENG Main Relay Terminal Identification

Feeback

Control

B+ - Coil

B+ - Switch

Front of Vehicle

Test Description

  1. Listen for an audible click when the relay operates. Repeat the commands as necessary.

Step

Action

Values

Yes

No

Schematic References: Engine Controls Schematics in Engine Controls - 2.5L (LBK)

Connector End View References: Engine Control Module Connector End Views or Engine Controls Connector End Views in Engine Controls - 2.5L (LBK)

1

Did you perform the Diagnostic System Check - Engine Electrical?

--

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2

Are DTCs P1610 or P1611 also set?

--

Go to Diagnostic Trouble Code (DTC) Listin Engine Controls - 2.5L (LBK)

Go to Step 3

3
  1. Start the engine.
  2. Measure the voltage at the battery with a DMM.
  3. Observe the Ignition 1 Signal parameter with a scan tool.
  4. Subtract the battery voltage from the voltage indicated on the Ignition 1 Signal parameter.

Is the voltage difference less than the specified value?

1 Volt

Go to Step 4

Go to Step 5

4
  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. 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 5

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

5

Remove and install the ENG MAIN relay. Repeat the procedure as necessary.

Do you hear an audible click when the relay is remove and installed?

--

Go to Step 8

Go to Step 6

6
  1. Turn OFF the ignition.
  2. Disconnect the ENG MAIN relay.
  3. Disconnect the ECM 1 fuse in the underhood fuse block.
  4. Measure the resistance of the battery positive circuit of the ENG MAIN relay coil from the ECM 1 fuse terminal to the relay terminal.

Is the resistance less than the specified value?

3 ohms

Go to Step 7

Go to Step 16

7
  1. Turn ON the ignition, with the engine OFF.

    2. Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms.

  2. Probe the control circuit of the ENG MAIN relay with a test lamp connected to battery positive voltage.
  3. Measure the voltage from the probe of the test lamp to a good ground with a DMM.

Is the voltage less than the specified value?

2.5 V

Go to Step 14

Go to Step 13

8
  1. Turn OFF the ignition.
  2. Disconnect the ENG MAIN relay.
  3. Probe the battery positive circuit of the ENG MAIN relay switch with a test lamp connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 17

9

    Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms.

  1. Probe the battery positive circuit of the ENG MAIN relay switch with a test lamp connected to a good ground.
  2. Measure the voltage from the probe of the test lamp to battery positive voltage with a DMM.

Is the voltage less than the specified value?

0.1 Volts

Go to Step 10

Go to Step 17

10
  1. Connect a 15-ampere fused jumper wire from battery positive voltage to the ENG MAIN relay switched output terminal at the fuseblock for the feedback circuit of the ENG MAIN relay.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage at the battery with a DMM.
  4. Observe the Ignition 1 Signal parameter with a scan tool.
  5. Subtract the battery voltage from the voltage indicated on the Ignition 1 Signal parameter.

Is the voltage difference less than the specified value?

1 Volt

Go to Step 14

Go to Step 11

11
  1. Turn OFF the ignition.
  2. Disconnect the ECM.
  3. Connect a 15-ampere fused jumper wire from battery positive voltage to the ENG MAIN relay switched output terminal at the fuseblock for the feedback circuit of the ENG MAIN relay.
  4. Connect a test lamp from the feedback circuit of the ENG MAIN relay at the harness connector of the ECM to a good ground.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 18

12

    Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms.

  1. Connect a test lamp from the feedback circuit of the ENG MAIN relay at the harness connector of the ECM to a good ground.
  2. Measure the voltage from the probe of the test lamp to battery positive voltage with a DMM.

Is the voltage less than the specified value?

0.3 Volts

Go to Step 15

Go to Step 18

13

Test the control circuit of the ENG MAIN relay for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 15

14

Test for an intermittent or poor connection at ENG MAIN relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairsin Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 19

15

Test for an intermittent or poor connection at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairsin Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 20

16

Repair the high resistance in the battery positive voltage circuit of the ENG MAIN relay coil. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 21

--

17

Repair the high resistance in the battery positive voltage circuit of the ENG MAIN relay switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 21

--

18

Repair the feedback circuit of the ENG MAIN relay for one of the following conditions.

    • An open
    • High resistance

       Important: If a short to ground is indicated by an open ENG 1 fuse. Test all circuits protected by the fuse.

    • A short to ground

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 21

--

19

Replace the ENG MAIN relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

--

Go to Step 21

--

20

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls - 2.5L (LBK).

Did you complete the replacement?

--

Go to Step 21

--

21
  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 22

22

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) Listin Engine Controls - 2.5L (LBK)

System OK