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P2509 Fault Code in 2007 Dodge Ram 2500: Causes and DIY Solutions

Model: 2007 Dodge Ram 2500 Fault Code: P2509 Posted: 2015-07-11 15:03

I own a 2007 Dodge Ram 2500. A few months ago, I replaced the battery after the engine light remained on while driving, despite all systems functioning normally. The truck eventually drained completely and required jump-starting. After replacing the second battery, the engine light is still illuminated. When connected to a diagnostic machine, it displays the P2509 ECM/PCM Power fault code. Is there a way to clear this code myself without visiting the dealership? The P2509 code indicates: 'Loss of voltage detected at the ECM for a calibrated amount of time.' Possible causes include: - Poor battery connections - Low battery voltage - Open fuse between B+ and ECM - Open ground circuit - Battery positive terminal shorted to other circuits - Return circuit shorted - Battery positive shorted to ground - Intermittent electrical issues I’ve already cleaned the battery terminals, but the issue persists. I’m looking for a reliable, cost-effective solution that doesn’t require dealer service. Any advice on troubleshooting or resetting this code would be greatly appreciated.

Related fault codes
P2509
Comments (6)
Anonymous 2015-07-11 16:57

P2509: Set Condition - Loss of voltage detected at the ECM for a calibrated amount of time. Possible Causes: - Poor connections at battery terminals - Low battery voltage - Open fuse between B+ and ECM - Open ground circuit - Battery positive shorted to other circuits - Return circuit shorted - Battery positive shorted to ground - Intermittent electrical condition Check these points thoroughly. The code can often be cleared using an OBD2 scanner, followed by several drive cycles under normal operating conditions. Knowing the specific engine type and whether there are aftermarket parts (like remote starters) would help narrow down the diagnosis.

Anonymous 2015-09-26 20:52

If the alternator diode is leaking, does it emit a burning smell? I'm experiencing P2509 along with codes P2503 and P2502. This could indicate an electrical failure in the charging system.

Anonymous 2015-09-27 09:34

Consider checking TSB 18-001-07 for your 2007 Dodge Ram 2500 — it may address this issue. A local Dodge dealer might be able to confirm if the technical service bulletin applies to your vehicle.

Anonymous 2015-11-02 08:43

What does 'Battery + Shorted to Other Circuits' mean? Does this refer to a short between the positive terminal and another electrical wire or component, such as a sensor or fuse?

Anonymous 2015-12-19 10:46

I have a 2007 Dodge Ram 2500 with only the P2509 code appearing during cold weather starts. I've cleaned the battery terminals and still no improvement. What should be my next troubleshooting step?

Anonymous 2015-12-19 10:55

prs wrote: I have a 2007 Dodge Ram 2500 with only the P2509 code appearing during cold weather starts. I've cleaned the battery terminals and still no improvement. What should be my next troubleshooting step? This suggests possible issues with battery performance in low temperatures or alternator output under cold conditions.