B1318 on RAM 3500
Factory diagnostic protocol and troubleshooting wire for fault code B1318 specifically for the RAM 3500 (2020–2026, 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel)).
1. Symptoms of B1318 on RAM 3500
When the Engine Control Module (ECM/PCM) on your RAM 3500 (6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel)) logs fault code B1318, drivers commonly observe:
2. Most Likely Causes on RAM 3500
Historical warranty claims and technical repair bulletins for RAM 3500 point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for RAM 3500
Measure resting battery voltage with engine off. Normal is 12.6V. If under 12.0V, battery is discharged. on the RAM 3500 equipped with 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel).
Remove corrosion with baking soda solution and wire brush, tighten terminal clamps firmly. on the RAM 3500 equipped with 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel).
Start engine and measure voltage across battery. Normal charging voltage is 13.8V to 14.6V. If below 13.0V, alternator has failed. on the RAM 3500 equipped with 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel).
Install new high-CCA AGM or flooded battery, or replace alternator. on the RAM 3500 equipped with 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel).
Clear DTCs and perform Battery Management System (BMS) reset if equipped. on the RAM 3500 equipped with 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel).
Equipment for Diagnosing RAM 3500 (B1318)
RAM 3500 OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for RAM 3500.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on RAM 3500
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the RAM 3500:
4. RAM 3500 B1318 FAQs
What causes code B1318 to trigger on a RAM 3500?
On the RAM 3500 (6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel)), B1318 is most frequently caused by Failing 12V automotive battery (sulfated plates or dead cell) or Faulty alternator not charging battery (>13.5V).
Where is the OBD-II port located on my RAM 3500?
On the RAM 3500, the 16-pin DLC diagnostic connector is located Driver lower kick panel near emergency brake assembly. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my RAM 3500 with code B1318?
Caution. Low voltage (<10V) causes random module dropouts, flickering dash lights, and stalling. Given that B1318 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

