P2507: ECM/PCM Power Input Signal Low

What it means

The ECM/PCM power input signal is below the expected range. The code does not establish whether the cause is the battery, wiring, relay, or another part of the supply circuit.

At a glance

• Usually lights the check-engine light

How it works

The ECM or PCM needs an adequate power supply from the battery through its fuses, relay, wiring, and connectors. P2507 sets when the module's power input falls below its expected range, but the code alone does not show whether the battery, relay, or feed circuit is responsible.

Common causes

Most likely first.

1. Main relay does not pull in
2. Open supply wire
3. Severely discharged battery

Symptoms

• Check-engine light
• Slow cranking or no-start
• Intermittent stalling

How to diagnose it

1. Record freeze-frame data and check live battery or module supply data, if available, to see whether the low input occurred during cranking or while running.
2. Inspect battery terminals, module power-feed connectors, and visible wiring for corrosion, looseness, or damage.
3. Check battery condition and charge state, then test the ECM/PCM power-feed fuses and main relay.
4. Measure power and ground at the module during cranking and compare the results with the manufacturer's specification.
5. If battery and relay operation are sound, check the power-feed wire and connections for an open circuit or excessive voltage drop.

Common fixes

• Charge or replace a severely discharged or failed battery after testing it.
• Clean and tighten corroded battery or ECM/PCM power connections.
• Replace a failed main relay or blown power-feed fuse after checking the circuit.
• Repair an open or damaged module supply wire.

Can I keep driving?

The vehicle may crank slowly, stall, or fail to start if module power is too low. Avoid relying on it for a trip until the battery and feed circuit are checked, especially if the engine has already cut out.