B1973 — Passenger Rear Seat Down Switch Circuit Short to Battery

body electrical

Is it safe to drive?

Short-term driving is OK Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B1973 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the body electrical system for damage, corrosion, chafing or poor contact.
Subsystem check Operate the affected function while watching its switch and motor PIDs in live data.
Subsystem check Inspect connectors and wiring at flex points (door jambs, tailgate hinges) — wires break there first.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1973 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1973 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; BCM repair or replacement: $300–$900; Replace the switch or actuator: $120–$450. Overall, fixing B1973 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code B1973 mean?

Passenger Rear Seat Down Switch Circuit Short to Battery (B1973): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

Will B1973 clear itself?

Sometimes B1973 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose B1973 myself?

Start with a scan: confirm B1973, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the body electrical system, and verify the suspect component against live data before buying parts.

What is the most common cause of B1973?

The most common causes are: damaged wiring in door jambs or wet areas, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

Is it safe to drive with B1973?

Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

When your vehicle's computer decides something is wrong with the passenger rear seat down switch circuit, it logs code B1973. This trouble code tells you that the body control module has detected a short to battery voltage somewhere in that specific circuit. In plain language, the switch or wiring is getting power when it should not be, or the module is seeing a signal that does not match what it expects under normal conditions.

B1973 falls within the body electrical category of OBD2 codes, which means the problem lives in the systems that handle comfort and convenience features rather than engine management. The module does not trigger this warning after a single bad reading. It watches the circuit over time and across specific operating conditions before it decides the fault is real and turns on the check engine light. That is why the freeze frame data stored alongside B1973 is so useful — it records engine load, RPM, coolant temperature, and vehicle speed at the exact moment the fault occurred. You can use those numbers to recreate the situation and catch the problem while you are testing.

The body control module serves as the nerve center for most electrical accessories in the car. It monitors switches, actuators, and motors throughout the vehicle and commands them to respond when you press a button or close a door. When a short to battery appears in the passenger rear seat down switch circuit, the BCM receives incorrect voltage and logs B1973 to alert you that something in that chain of communication has gone wrong.

Symptoms of B1973

The check engine or warning light illuminates on the dashboard
The passenger rear seat adjustment or related accessory stops responding to switch commands
The affected function works only intermittently or fails completely
Other body electrical features may behave erratically if the BCM is overwhelmed by the fault
In most cases, the engine runs and drives normally — the problem stays confined to the body circuit
Some vehicles may experience dimming or flickering of interior lights due to voltage irregularities

Common Causes

The most frequent culprit behind B1973 is a faulty switch or actuator in the passenger rear seat circuit. Over time, the contacts inside the switch wear out, corrode, or develop internal shorts that send unwanted voltage back to the module.

Damaged or corroded wiring connectors rank second on the list. The harness running through door Jambs and near the seat tracks endures constant flexing, moisture exposure, and physical stress. Wires break or the insulation cracks, allowing battery voltage to contact signal wires and trigger the short condition the module detects.

A failing body control module itself can generate false B1973 codes. When the BCM internal circuits degrade or its software becomes corrupted, it may misinterpret normal signals as faults. This scenario costs the most to fix, which is why you should rule out simpler causes first.

Loose or unplugged connectors interrupt proper circuit communication and can create voltage spikes that look like shorts to the monitoring module. Vibration from normal driving loosens connections over time, particularly in older vehicles.

Blown fuses or failed relays in the accessory power circuit sometimes send unexpected voltage into adjacent circuits, creating cross-talk that the BCM interprets as a short condition.

How to Diagnose B1973

Pull the code with a quality OBD2 scanner and record the freeze frame data before doing anything else. That snapshot tells you whether the fault happened at idle, at highway speed, or when the engine was cold. Reproducing those exact conditions during your tests makes the problem much easier to catch.

Cross-reference any other trouble codes stored alongside B1973. Related codes in the B0xxx or U-series often point directly to the failing component. While you are researching, check manufacturer technical service bulletins for your specific make and model — some vehicles have known software updates or factory remedies for recurring body code issues.

Visually trace the wiring harness for the passenger rear seat switch circuit. Look for cracked insulation, rubbed-through wires near sharp metal edges, and any signs of moisture damage or corrosion on the connectors. Pay special attention to flex points where the harness bends through door Jambs or around seat tracks.

Operate the switch while monitoring live data on your scanner. Watch the voltage signal the BCM receives from that circuit. If the reading jumps unexpectedly or does not change when you press the switch, you have found your problem area.

Clear the code after your inspection and test drive the vehicle through the exact conditions captured in the freeze frame. If B1973 returns, you have confirmed an active fault rather than a one-time electrical glitch. A persistent code means you need to dig deeper into that specific circuit.

Repair Options and Costs

Wiring repairs and connector replacement represent the most affordable path forward. Depending on whether you need a few inches of new wire or an entire harness section, expect to pay between $80 and $250 for parts and labor at an independent shop.

If testing confirms the body control module itself has failed, BCM repair or replacement becomes necessary. Used modules cost less but require programming to your vehicle. Complete replacement with new or refurbished units and associated labor typically runs $300 to $900.

Replacing a faulty switch or actuator in the passenger rear seat circuit generally falls between $120 and $450, depending on the part cost and labor time for your specific vehicle.

Total Repair Cost

The final bill for B1973 depends entirely on which component caused the fault. The cheapest possible fix — repairing a loose connector or patching a small section of damaged wire — might run just $80. At the other end of the spectrum, a new BCM with programming could cost $900 or more. Most situations fall somewhere in between, which is why methodical diagnosis before buying parts saves money. Never assume the worst-case scenario is the correct one — start cheap, test thoroughly, and upgrade your diagnosis only when evidence demands it.

Can You Drive With B1973?

In most cases, B1973 does not prevent you from driving the vehicle safely. Body electrical faults rarely affect engine performance, transmission operation, or braking systems. However, the warning light on your dashboard should not be ignored indefinitely.

If the fault involves exterior lighting circuits, your headlights or taillights could fail without notice — a serious safety concern after dark or in poor weather. Wiper motor failures create visibility problems during rain or snow. Central locking faults that stem from the same BCM issue could leave your car unsecured or trap you inside if the lock mechanism seizes.

Use your best judgment. If the only symptom is an illuminated light and all accessories work normally, you can continue driving while scheduling a diagnostic appointment. If any safety-related function behaves erratically, address the problem before your next long trip.