DTC 113 — Electrical System B+ Voltage Out of Range – Low — International DT466E

DTC 113 on International DT466E (1996–2003) indicates the ECM is seeing battery voltage below its valid range. Low B+ can affect injector drive and starting…

Updated October 15, 2026

What it means

On the DT466E, DTC 113 means battery voltage at the ECM is below its valid range. This is a Navistar three-digit flash code, not an OBD-II P-code. Typical on this platform: weak batteries, a failing alternator or poor battery/ground connections; low voltage also hurts injector drive and starting.¹

Most likely causes

1. Weak or discharged batteries — Aged or discharged batteries cannot hold voltage under load, causing ECM B+ to read low at idle or during cranking.¹
2. Failing alternator or voltage regulator — Reduced charging output lets system voltage sag, especially with electrical loads on.¹
3. Poor battery or chassis/engine ground connections — Corrosion, loose terminals or damaged cables raise resistance and drop voltage seen by the ECM.¹
4. High-resistance positive feed to the ECM — Oxidized or loose power distribution points, fusible links or battery cables can starve the ECM of B+.¹

How to diagnose

1. Verify the code is active and note freeze-frame conditions (engine off, idle, or under load).
2. Measure battery open-circuit voltage and voltage during cranking; compare to spec.
3. Check charging voltage at the battery with engine running at fast idle and loads on; look for low output.
4. Inspect battery terminals, chassis and engine grounds, and ECM power feeds for corrosion, looseness or heat damage.
5. Load-test batteries and test alternator output; repair/replace as needed, then clear codes and retest.
6. If voltage is normal but DTC 113 returns, inspect wiring and connectors between battery and ECM for intermittent high resistance.
7. Document results and confirm no related low-voltage symptoms remain.

Specs and test values

Parts and tools you may need

• Digital multimeter
• Battery load tester
• Alternator tester
• Terminal cleaning brush
• Basic hand tools

Tools you’ll need

• digital multimeter — Measures battery open-circuit, cranking, and charging voltages to confirm ECM under-voltage conditions.
• battery load tester — Identifies weak or discharged batteries that can cause ECM voltage to drop below valid range.
• alternator tester — Checks alternator output and voltage regulator performance under load to rule out charging faults.
• wire brush — Cleans corrosion from battery terminals, chassis and engine grounds, and ECM power feeds to restore proper voltage.

Rough cost and difficulty

Typical US independent-shop figures; labor runs about $140–$200 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If voltage tests are inconclusive, wiring faults are suspected, or the code returns after parts replacement, have a qualified diesel technician diagnose the charging and ECM power circuits. Do not attempt repairs on high-pressure oil or injector circuits for this code.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources