Battery voltage supplies the PCM with long term memory. Diagnostic trouble codes (DTC) and engine control parameters that were learned are kept in the PCM memory even when the ignition is OFF. A DTC P1510 sets, and the PCM long term memory information is lost when the circuit voltage in the memory power input is interrupted.
• | There is not a back-up power supply 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 a DTC P1510 as long as the ignition remains ON. |
• | The MIL turns OFF after three consecutive trips, during which the diagnostic runs and a fault is not detected. |
• | A History DTC clears after 40 consecutive warm-up cycles without a fault. |
• | Use the Clear DTC Information function on the scan tool, or disconnect the PCM battery feed in order to clear the DTC. |
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 a DTC P1510, and a DTC P1510 will not be stored.
Check for a blown fuse. Replace any blown fuses, and retest the diagnostic.
A fault in the memory power input circuit may cause an intermittent malfunction. Inspect the wiring harness and the components for any of the following conditions:
• | Backed out terminals |
• | Incorrect mating of terminals |
• | Broken electrical connector locks |
• | Incorrectly formed terminals or damaged terminals |
• | Faulty terminal-to-wire connections |
• | Physical damage to the wiring harness |
• | A broken wire inside the insulation |
• | Corrosion of electrical connections, of splices, or of terminals |
The numbers below refer to the step numbers in the diagnostic table.
The Powertrain OBD System Check prompts the technician to complete some basic checks, and to save the applicable Freeze Frame data on the scan tool. This creates an electronic copy of the data that was taken when the fault occurred. The scan tool saves the information for later reference.
This step determines if a fault is present.
This step checks for voltage at the PCM if the ignition is off. The PCM should indicate the battery voltage on this terminal during all operating conditions.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
Is a DTC P0113 indicated? | -- | Go to Diagnostic Aids | ||
Is the voltage near the specified value? | B+ | |||
4 |
Was a repair necessary? | -- | Go to Diagnostic Aids | |
5 |
Was a repair necessary? | -- | ||
6 | Replace the PCM. Is the action complete? | -- | -- | |
7 |
Does the scan tool display any DTCs? | -- | Go to the applicable DTC table | System OK |