hey can someone shed some light on what I'm to search for with a P 2509 code.

onetun

 

P2509-POWERDOWN DATA LOST ERROR




For a complete wiring diagram Refer to Section 8W.

When Monitored:
Continuous - key on or key off.

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

Possible Causes
POOR CONNECTIONS AT THE BATTERIES
LOW BATTERY VOLTAGE
OPEN FUSED B+ TO ECM
OPEN GROUND CIRCUIT
BATTERY + SHORTED TO OTHER CIRCUITS
RETURN CIRCUIT SHORTED
BATTERY + SHORTED TO GROUND
INTERMITTENT CONDITION


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Diagnostic Test
1. POOR CONNECTIONS AT THE BATTERIES

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



2. LOW BATTERY VOLTAGE

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



3. OPEN FUSED B+ TO ECM

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



4. OPEN GROUND CIRCUIT

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



5. BATTERY + SHORTED TO OTHER CIRCUITS

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



6. RETURN CIRCUIT SHORTED

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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 VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



7. BATTERY + SHORTED TO GROUND

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

Is the resistance greater than 100k Ohms?

Yes
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

No
Repair Battery + shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

 

Wow, now that is a nice troubleshooting guide. My truck had the 2509 code at around 4000 miles. it went away after 2 days. I actually had an appointment with the dealer the day it went out. I never went since they would have needed to see the light to do anything about it.

Thanks for that info

 

Came staight from Daimler! Hope it helps you out!

Andy