P2509

P2509-POWERDOWN DATA LOST ERROR





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

Continuous - key on or key off.

- Set Condition:

Loss of voltage detected at the ECM for a calibrated amount of time.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. POOR CONNECTIONS AT THE BATTERIES

Visually inspect the wiring at the battery for damaged wires, or corrosion.

Are the connections tight and free of corrosion?

Yes

- Go To 2

No

- Repair the poor connections at the batteries.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. LOW BATTERY VOLTAGE

Measure the voltage between the positive and negative posts of the batteries.

Is the battery voltages both above 12 volts?

Yes

- Go To 3

No

- Recharge or replace the battery (s).
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. OPEN FUSED B+ TO ECM





Turn the ignition off.

Disconnect the ECM harness connectors.

Turn the ignition on.

Measure the resistance between the positive battery post and the ECM supply circuits.

Is the resistance less than 10 Ohms?

Yes

- Go To 4

No

- Repair the open fused B+ circuit to ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. OPEN GROUND CIRCUIT





Measure the resistance between the negative battery post and the ECM ground circuits.

Is the resistance less than 10 Ohms?

Yes

- Go To 5

No

- Repair the open ground circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. BATTERY + SHORTED TO OTHER CIRCUITS





Measure the resistance between the ECM supply circuits and all other circuits in the ECM harness connector, except other supply circuits.

Is the resistance greater than 100k Ohms?

Yes

- Go To 6

No

- Repair the battery circuit short to other circuits in engine harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. RETURN CIRCUIT SHORTED





Measure the resistance between the ECM return circuits and all other circuits in the ECM harness connector, except other return circuits.

Is the resistance greater than 100k Ohms?

Yes

- Go To 7

No

- Repair or replace the engine harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. BATTERY + SHORTED TO GROUND





Measure the resistance between the ECM B+ supply circuits and ground.

Is the resistance greater than 100k Ohms?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

No

- Repair Battery + shorted to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test