Circuit Description
The engine control module (ECM) monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect input can occur when the voltage is out of range. The ECM monitors the system voltage over an extended length of time. 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 vehicle speed is above 8 km/h (5 mph). |
| • | The system voltage is between 9.5-18 volts. |
Conditions for Setting the DTC
The ECM detects a system voltage below 10 volts for 5 seconds.
Action Taken When the DTC Sets
| • | The ECM will command the charge indicator to be illuminated on the instrument panel cluster (IPC). |
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
| • | The ECM will store conditions which were present when the DTC set as Fail Records data only. |
Conditions for Clearing the DTC
| • | The ECM will command the message OFF after one trip in which the diagnostic test has been 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 the scan tool Clear DTC Information function. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics or Starting and Charging Schematics Connector End View Reference: Engine Control Module Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the Ignition 1 Signal parameter is greater than the specified value? | 10.5 V | Go to Step 7 | Go to Step 3 |
3 | Measure the voltage at the battery terminals and compare it with the Ignition 1 Signal parameter in the ECM data list. Are the battery voltage and Ignition 1 Signal readings different by more than the value specified? | 0.5 V | Go to Step 4 | Go to Charging System Test |
4 | Test the battery positive voltage circuit of the ECM for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 5 |
5 | Test the ground circuit of the ECM for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6 |
6 | Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7 |
7 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 8 | -- |
8 |
Does the scan tool indicate that DTC P0562 failed this ignition? | -- | Go to Step 2 | System OK |
