Circuit Description
The engine control module (ECM) monitors the main relay switched voltage on 3 parallel circuits that travel between the underhood fuse block and the ECM. These circuits are tied together internally in the ECM. When ignition voltage is present at the ignition 1 input to the ECM, the ECM will command the main relay ON by grounding the control circuit of the main relay. When the main relay is energized, battery voltage should be present on each ignition 1 circuit at the ECM. The ECM monitors the voltage over an extended length of time. If the ECM detects a voltage outside an expected range for the calibrated length of time, DTC P0560 will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0560 System Voltage
Conditions for Running the DTC
| • | The main relay is commanded ON by the ECM. |
| • | The engine has been running for more than 3 minutes. |
Conditions for Setting the DTC
Circuit voltage is below 2.5 volts for longer than 3 seconds.
Action Taken When the DTC Sets
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
| • | The ECM will command a message to be displayed. |
| • | The ECM will store conditions which were present when the DTC set as Failure 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 | Value | Yes | No |
|---|---|---|---|---|
Connector End View Reference: Engine Control Module Connector End Views in Engine Controls - 3.0L (L81) or Power and Grounding Connector End Views in Wiring Systems | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool indicate that DTC P0560 has passed this ignition cycle? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the scan tool indicate that the Ignition 1 parameter is greater than the specified value? | 2.5 V | Go to Step 12 | Go to Step 4 |
4 | Turn the ignition from the OFF to ON position. Does the main relay click each time the ignition changes position? | -- | Go to Step 6 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 9 | Go to Step 7 |
6 |
Does the scan tool indicate that the main relay parameter is greater than the specified value? | 2.5 V | Go to Step 9 | Go to Step 8 |
7 | Test the control circuit of the main relay for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
8 | Test the main relay voltage circuit of the engine control module (ECM) for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
9 | Inspect for poor connections at the main relay. 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 13 | Go to Step 11 |
10 | Inspect for poor connections 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 13 | Go to Step 12 |
11 | Replace the main relay. Did you complete the replacement? | -- | Go to Step 13 | -- |
12 |
Important: The replacement ECM must be programmed. 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 13 | -- |
13 |
Does the scan tool indicate that DTC P0560 failed this ignition? | -- | Go to Step 3 | System OK |
