P2509
P2509-POWERDOWN DATA LOST ERRORP2509 - Powerdown Data Lost Error:
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.
Diagnostic Test
1. POOR CONNECTIONS AT THE BATTERIES
Visually inspect the wiring at the battery for damaged wires, or corrosion.
Q: Are the connections tight and free of corrosion?
YES: Go To 2
NO: Repair the poor connections at the batteries. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
2. LOW BATTERY VOLTAGE
Measure the voltage between the positive and negative posts of the batteries.
Q: Is the battery voltages both above 12 volts?
YES: Go To 3
NO: Recharge or replace the battery (s). Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
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.
Q: Is the resistance less than 10 Ohms?
YES: Go To 4
NO: Repair the open fused B+ circuit to ECM. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
4. OPEN GROUND CIRCUIT
Measure the resistance between the negative battery post and the ECM ground circuits.
Q: Is the resistance less than 10 Ohms?
YES: Go To 5
NO: Repair the open ground circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
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.
Q: Is the resistance greater than 100k Ohms?
YES: Go To 6
NO: Repair the battery circuit short to other circuits in engine harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
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.
Q: Is the resistance greater than 100k Ohms?
YES: Go To 7
NO: Repair or replace the engine harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
7. BATTERY + SHORTED TO GROUND
Measure the resistance between the ECM B+ supply circuits and ground.
Q: Is the resistance greater than 100k Ohms?
YES: Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
NO: Repair Battery + shorted to ground. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1