The DTC P1510 Control Module Long Term Memory Reset monitors the battery voltage supply to the PCM. The battery positive voltage circuit supplies power to the powertrain control module (PCM) for the retention of long term memory data. Diagnostic trouble codes and learned engine control parameters are kept in the PCM memory even when the ignition is Off. The PCM sets DTC P1510 and loses long term memory when the battery positive voltage circuit is interrupted.
The engine is running.
• | No back-up power is supplied to the PCM after starting the engine. |
• | The condition is present for 5 seconds. |
• | The PCM illuminates the malfunction indicator lamp (MIL). |
• | The PCM stores DTC P1510 as long as the ignition is not turned OFF. |
• | The PCM turns OFF the MIL after 3 consecutively passing trips. |
• | The PCM clears a history DTC after 40 consecutive warm-up cycles without a fault. |
• | Perform the scan tool Clear DTC Information function. |
The PCM will indicate a DTC P1510 as long as the ignition is On. As soon as the ignition is turned Off the PCM will lose memory of DTC P1510 and DTC P1510 will not be stored.
Check for an open fuse. Replace any open fuses and retest.
If the DTC P1510 is intermittent, driving the vehicle under the following conditions can verify whether the fault is present. Perform the scan tool Clear DTC Information function. Road test the vehicle while monitoring the DTC P1510 diagnostic on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If DTC P1510 appears in the Not Ran Since Code Cleared list, the P1510 diagnostic has not yet run. When DTC P1510 does not appear in the Not Ran Since Code Cleared list, the P1510 diagnostic has run. If the MIL is NOT illuminated and there is no Pending DTC Status in DTC Information, the P1510 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. The Not Ran Since Code Cleared list only indicates whether or not the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status in order to determine the outcome of the diagnostic test involved.
An intermittent malfunction may be caused by a problem in the battery positive voltage circuit. Inspect the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions .
The numbers below refer to the step numbers in the diagnostic table.
The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
This step determines if the fault is present.
This step checks for voltage at the PCM when the ignition is OFF. The PCM should indicate battery voltage on this terminal under all operating conditions.
Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P01510 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If a DTC P01510 appears in the Not Ran Since Code Cleared list, the DTC P01510 diagnostic has not yet run. When the DTC P01510 does not appear in the Not Ran Since Code Cleared list, the DTC P01510 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P01510 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | ||
Is a DTC P1510 set? | -- | Go to Step 3 | Go to Diagnostic Aids | |
Is the voltage near the specified value? | B+ | Go to Step 5 | Go to Step 4 | |
4 |
Was a repair necessary? | -- | Go to Step 7 | -- |
5 | Check for a poor connection at the PCM. Repair as necessary. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Was a repair necessary? | -- | Go to Step 7 | Go to Step 6 |
6 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did You complete the replacement? | -- | Go to Step 7 | -- |
Does the DTC run and pass? | -- | Go to Step 8 | Go to Step 2 | |
8 | With the scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |