B1316 — Battery Saver Relay Coil Circuit Short To Ground #

Note: The wording of code B1316 may differ depending on the vehicle manufacturer (OEM). Always refer to OEM service information for vehicle-specific definitions.

• Battery Saver Relay Coil Circuit Short To Ground (Ford, Lincoln, Mercury)
• Battery Saver Relay Circuit Shorted to Ground (Mazda)
• Battery Saver Relay Control Circuit Low (Jaguar, Land Rover)

Overview of Code B1316 #

The B1316 code is an OBD-II (On-Board Diagnostics II) body code that indicates an electrical problem detected in the Battery Saver Relay Coil Circuit. Specifically, it signals that the circuit is shorted to ground, meaning there’s an unintended electrical path directly to the vehicle’s chassis or earth point. This relay is part of the system that automatically turns off interior lights and other accessories after the ignition is off, preserving the vehicle’s battery. When your car’s computer detects this fault, it either disables the battery saver function or triggers a warning. If left unchecked, it can cause battery drain or prevent accessories from operating correctly.

Common Symptoms for Code B1316 #

When code B1316 triggers, several symptoms may appear—some subtle, others more obvious. The most frequent sign is that the vehicle’s interior lights may not turn off as expected. In other cases, drivers notice unusual behavior from powered accessories, or even a drained battery after the vehicle sits for a while. Here’s what to watch for:

• Interior lights remain on after the car is turned off
• Accessories (radio, power outlets) stay powered when they should automatically shut down
• Battery goes flat overnight or after extended parking
• Warning lights or error messages on the dashboard (sometimes “battery saver active” or similar)
• No audible warning chimes when doors are open with the key off

Most Likely Causes for Code B1316 #

The B1316 code typically results from an electrical fault involving the relay or its wiring. Some causes are more common than others, and understanding the likely culprits can save time during diagnosis. Here are the most frequent causes, in order:

1. Short circuit in the relay coil wiring harness (damaged insulation, pinched wires, or contact with metal parts)
2. Faulty battery saver relay (internal short or stuck contacts)
3. Corroded or loose ground connections (especially where the relay is grounded to the chassis)
4. Faulty body control module (BCM) or related control unit (rare, but possible if wiring and relay are OK)
5. Aftermarket accessory installation errors (improperly tapped wires or poor-quality splices)

Step-by-Step Diagnosis for Code B1316 #

Diagnosing a B1316 code requires a logical approach and some basic electrical tools. Always start with a visual inspection before diving into component testing. Here’s a proven step-by-step process:

• Step 1: Read and record all related OBD-II codes using a scan tool. Clear codes and see if B1316 returns after cycling the ignition.
• Step 2: Inspect the battery saver relay and its wiring harness for visible damage, corrosion, or loose connectors.
• Step 3: Check for blown fuses related to the battery saver circuit and replace if necessary.
• Step 4: Test the relay using a multimeter. Remove the relay, measure coil resistance, and check for continuity between coil and ground. Replace if readings are out of spec.
• Step 5: Trace the relay coil wiring from the relay socket to the BCM (body control module). Look for shorts to ground or damaged insulation using a test light or ohmmeter.
• Step 6: Confirm that all ground connections near the relay are clean, tight, and free of corrosion.
• Step 7: If all wiring and the relay check out, suspect a fault in the BCM or related module. Perform OEM-specific testing or seek professional assistance.

Possible Repairs for Code B1316 #

Once you’ve pinpointed the cause, repairs will focus on restoring normal electrical function to the battery saver relay circuit. Here are the most common solutions, depending on what you’ve found:

• Repair or replace damaged wiring that’s shorting to ground
• Replace a faulty battery saver relay if it fails continuity or resistance tests
• Clean and retighten ground terminals involved in the relay circuit
• Replace blown fuses and verify correct amperage
• Correct any aftermarket wiring errors, reroute or insulate wires as needed
• Replace or reprogram the BCM if diagnosed as defective (rare)

Can You Drive With Code B1316? #

Limited—Proceed With Caution: While code B1316 does not immediately endanger vehicle safety, it should not be ignored. If the battery saver circuit isn’t working, your battery could drain unexpectedly, potentially leaving you stranded. If you notice interior lights or accessories staying on after shutdown, address the issue as soon as possible to avoid further inconvenience and battery damage.

Vehicles Most Frequently Affected by Code B1316 #

The B1316 code is most common in certain Ford, Lincoln, and Mercury models, as well as some Mazda, Jaguar, and Land Rover vehicles. It is typically seen in cars, trucks, and SUVs that rely on a battery saver relay for interior lighting and accessory control. Here are examples:

• Ford F-150 (various years)
• Ford Taurus, Explorer, Expedition
• Lincoln Navigator, Town Car
• Mercury Grand Marquis, Mountaineer
• Mazda Tribute
• Jaguar X-Type, S-Type (certain years)
• Land Rover Freelander

Common Mistakes & Best Practices for Code B1316 #

Misdiagnosis is possible if you skip steps or overlook simple problems. Following best practices can help you avoid wasted time and money:

• Don’t replace the BCM before thoroughly checking wiring and relay. The control module is expensive and rarely fails compared to wiring issues.
• Always inspect for aftermarket alarm or remote start installations—these often cause wire shorts in older vehicles.
• Use a wiring diagram to trace the correct circuit; guessing can lead to missed faults.
• Never bypass the relay with a jumper wire—this can cause further electrical damage or fire risk.
• Clear codes after repair and confirm the fix by cycling the ignition and monitoring symptom return.

Quick FAQ for Code B1316 #

Even after reading a detailed guide, many drivers and technicians have lingering questions. Here are some quick answers:

• Q: Does code B1316 mean my battery is bad?
  A: Not directly. It means the relay circuit designed to protect your battery isn’t working right—if ignored, it could eventually drain your battery.
• Q: Can I just remove the relay to stop battery drain?
  A: Removing the relay may disable some accessories and lighting, but it’s not a permanent fix. Find and repair the root cause to restore proper function.