Schematic Reference: Engine Controls Schematics
Battery voltage is supplied to the ECM for the retention of certain long term memory data. Diagnostic trouble codes (DTC) and learned engine control parameters are kept in the ECM's memory even when the ignition is OFF. A DTC P1510 sets and the ECM long term memory information is lost when the memory power input circuit voltage is interrupted.
• | No back-up power supply to the ECM after starting the engine. |
• | Condition is present for 5 seconds. |
• | The ECM illuminates the malfunction indicator lamp (MIL). |
• | The ECM stores a DTC P1510 as long as the ignition is not turned OFF. |
• | The MIL turns OFF after three consecutively passing trips without a fault present. |
• | A History DTC clears after 40 consecutive warm-up cycles without a fault. |
• | Use the scan tool Clear DTC Information function or disconnect the ECM battery feed in order to clear the DTC. |
The ECM will indicate a DTC P1510 as long as the ignition is ON. As soon as the ignition is turned OFF the ECM will lose its memory of a DTC P1510 and a DTC P1510 will not be stored.
Check for a blown fuse. Replace any blown fuses and retest.
An intermittent malfunction may be caused by a problem in the memory power input circuit. Inspect the wiring harness and components for any of the following conditions:
• | Backed out terminals. |
• | Improper mating of terminals. |
• | Broken electrical connector locks. |
• | Improperly formed or damaged terminals. |
• | Faulty terminal to wire connections. |
• | Physical damage to the wiring harness. |
• | A broken wire inside the insulation. |
• | Corrosion of electrical connections, splices, or 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 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 ECM when the ignition is off. The ECM should indicate battery voltage on this terminal under 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 | Check the memory power circuit for an open or a short between the ECM and the fuse block 2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Was a repair necessary? | -- | Go to Diagnostic Aids | |
5 | Check for a poor connection at the ECM. Repair as necessary. Was a repair necessary? | -- | ||
6 | Replace the ECM. Refer to Engine Control Module Replacement. Is the action complete? | -- | -- | |
7 |
Are any DTCs displayed on the scan tool? | -- | Go to the Applicable DTC Table | System OK |