B1989 — Pedal Position Rearward Switch Circuit Short to Battery #

Note: The exact wording of this DTC (Diagnostic Trouble Code) may vary depending on the vehicle manufacturer.

• Ford: Pedal Position Rearward Switch Circuit Short to Battery
• Lincoln: Pedal Position Rearward Switch Short to B+
• Mercury: Pedal Position Rearward Switch Circuit High

Summary of code B1989 #

The B1989 code indicates that the vehicle’s pedal position rearward switch circuit is experiencing a short to battery voltage. In simple terms, this means the electrical circuit that monitors the rearward position of the adjustable pedals is receiving voltage when it shouldn’t, likely due to a wiring or switch fault. This code is most often detected by the Body Control Module (BCM) or a similar onboard controller, which continuously monitors the position sensor circuits. While this fault is not usually engine-related, it can affect comfort and safety features tied to pedal adjustment. Prompt diagnosis is important to avoid further electrical issues or loss of pedal adjustment functionality.

Common symptoms for code B1989 #

When the B1989 code is present, you may notice a range of symptoms. These are usually minor inconveniences but can be frustrating if you rely on adjustable pedals for comfort or accessibility. Look for the following:

• Adjustable pedals not responding to input or failing to move
• Pedals moving only in one direction (forward or rearward)
• Warning light or message on the dashboard
• Body control-related warning stored in the vehicle’s memory
• In rare cases, electrical noises or clicking sounds from the pedal area

Most probable causes for code B1989 #

Causes for a short to battery in the pedal position rearward switch circuit often center around electrical faults or component failures. Here are the most likely culprits, ranked by frequency:

1. Damaged or chafed wiring harness in the pedal adjustment area
2. Faulty pedal position rearward switch (internal failure)
3. Corroded, loose, or contaminated electrical connectors at the pedal or switch
4. Short-to-battery condition caused by an aftermarket accessory tap or incorrect repair
5. Faulty BCM (rare, but possible if all else is ruled out)

Step-by-step diagnosis for code B1989 #

Diagnosing B1989 requires a logical approach, starting with the basics and moving to more involved tests if needed. Here’s a guided path for technicians or skilled DIYers:

• 1. Scan for codes: Confirm B1989 and check for related codes (especially those tied to pedal or body control systems).
• 2. Visual inspection: Examine the pedal assembly, switch, and related wiring for signs of damage, pinching, or corrosion.
• 3. Connector check: Unplug the pedal position rearward switch connector. Inspect for corrosion, bent pins, or moisture.
• 4. Circuit test: With a multimeter, check for battery voltage present on the signal wire when the switch is disconnected. If voltage is present, there’s a short to battery upstream.
• 5. Switch test: Test the switch for proper open/closed operation per OEM specs. Replace if out of specification.
• 6. Wiring continuity: Check continuity and for shorts-to-power between the switch, BCM, and ground.
• 7. BCM testing (if needed): Only after all wiring and switch tests pass, consider BCM diagnosis or reprogramming per OEM guidelines.

Possible repairs for code B1989 #

Once the root cause is identified, repairs should be targeted and thorough. Each fix is directly tied to the earlier diagnostic steps:

• Repair or replace damaged wiring harness sections and secure away from moving parts
• Replace the pedal position rearward switch if faulty
• Clean, repair, or replace corroded or loose connectors
• Remove any improper aftermarket wiring tapping into the pedal circuit
• In rare cases, replace or reprogram the BCM if verified faulty

Is it safe to drive with code B1989? #

Yes, but with limitations. The B1989 code is not directly related to engine performance or braking. You can safely drive the vehicle, but the adjustable pedal feature may not work, which could affect comfort or driver ergonomics—especially for those who rely on this adjustment for proper reach. If the pedal feels loose, jammed, or moves unexpectedly, avoid driving and seek repairs immediately.

Vehicles most affected by code B1989 #

This code is most commonly reported in vehicles equipped with adjustable pedals, particularly those using Ford’s or affiliated brands’ systems in the early 2000s to mid-2010s. Models include:

• Ford F-150, F-250, and F-350 (2000s–mid-2010s)
• Ford Expedition, Explorer, and Flex
• Lincoln Navigator, Town Car
• Mercury Mountaineer
• Various other large SUVs and trucks with power adjustable pedals

Common mistakes & best practices with code B1989 #

Missteps in diagnosing or repairing B1989 often lead to wasted time or recurring problems. Here’s how to avoid common pitfalls:

• Replacing the switch without inspecting or repairing damaged wiring
• Overlooking connector corrosion or water intrusion
• Assuming the BCM is at fault without full circuit testing
• Neglecting to clear codes and verify repair with a full pedal function test
• Forgetting to check for aftermarket electrical modifications in the affected area

Quick FAQ for code B1989 #

Q: Will this code cause my vehicle to fail a state inspection?
A: Usually not, as it’s not an emissions or engine-related code. However, some jurisdictions may flag any active fault codes, so check local regulations.

Q: Can I fix this myself, or do I need a dealer?
A: If you’re comfortable with electrical diagnostics and have a wiring diagram, you can often resolve this yourself. For BCM programming or replacement, a dealer or experienced shop may be necessary.