B1623 — Lamp Keypad Output Circuit Failure #

Note: The code description may vary depending on the vehicle manufacturer.

• B1623: Lamp Keypad Output Circuit Failure (Generic / Ford / Chrysler / Others)
• B1623: Keyless Entry Keypad Lamp Output Circuit Malfunction (Ford)
• B1623: Keypad Backlighting Output Open Circuit (Chrysler)

Summary of code B1623 #

The B1623 diagnostic trouble code (DTC) indicates a malfunction in the lamp keypad output circuit. In simple terms, this refers to an electrical fault affecting the backlight or illumination system of the numeric keypad, typically found on the driver’s door or dashboard for keyless entry systems. The keypad lamp output is responsible for lighting the buttons so they can be seen at night or in low-light conditions. When the vehicle’s control module (often the Body Control Module or BCM) detects an anomaly—such as an open circuit, short, or unexpected resistance—it sets this code. Although this issue does not usually affect the engine or critical safety features, it can impact the convenience and usability of your keyless entry system.

Common symptoms for code B1623 #

When the B1623 code appears, symptoms are generally limited to the keyless entry keypad system. However, these can range from subtle to obvious, depending on vehicle design:

• Keypad backlight not illuminating when unlocking or approaching the vehicle
• Keyless entry keypad completely dark or only partially lit
• Intermittent keypad illumination (sometimes works, sometimes doesn’t)
• No response from keypad when buttons are pressed (if related circuits share a ground or power)
• Warning or error message on the instrument cluster (some OEMs)

Probable causes for code B1623 #

Several factors can trigger the B1623 code. The most common causes (from most to least likely) include:

1. Burnt-out keypad backlight bulb or LED
2. Damaged or corroded wiring/connectors in the keypad lamp output circuit
3. Faulty keypad assembly (internal circuit failure)
4. Blown fuse associated with the keypad lamp circuit
5. Faulty Body Control Module (BCM) or related control unit

Step-by-step diagnosis for code B1623 #

Diagnosing B1623 requires attention to both the physical components and the electronic control systems. Here’s a structured approach:

• Verify the code with a professional OBD-II/EOBD scanner; clear and see if it returns.
• Check if the keypad backlighting functions during vehicle unlock or approach.
• Visually inspect the keypad for damage, moisture ingress, or signs of wear.
• Inspect wiring and connectors between the keypad and the BCM for corrosion, pin damage, or breaks.
• Test keypad illumination circuit with a multimeter: check for power and ground at the keypad connector.
• Test the keypad lamp (bulb or LED) for continuity; replace if open or non-functional.
• Check the relevant fuses in the fuse box; replace if blown and investigate cause.
• If all wiring and components test OK, consider BCM testing or reprogramming.

Possible repairs for code B1623 #

Repair strategies depend on the root cause identified during diagnosis. Here are the most common solutions:

• Replace burnt-out keypad backlight bulb or faulty LED module
• Repair, clean, or replace damaged wiring and connectors in the keypad circuit
• Replace the entire keypad assembly if internal failure is confirmed
• Replace blown fuses and address the underlying cause of the short or overload
• In rare cases, repair or replace the Body Control Module (BCM) and perform necessary programming

Is it safe to drive with code B1623? #

Yes, you can drive your vehicle with this code present. The B1623 code is typically associated with the convenience features of your vehicle and does not affect essential engine, transmission, or safety systems. However, if you rely on the keypad for entry—especially in low-light conditions—prompt repair is recommended to avoid inconvenience.

Vehicles most commonly affected by code B1623 #

While B1623 can appear in any vehicle with a keyless entry keypad, it is most frequently reported in models from the following OEMs:

• Ford (including Lincoln and Mercury, especially mid-2000s to current)
• Chrysler (including Dodge and Jeep with keypad systems)
• Some late-model GM vehicles with optional keypad entry
• Select Asian and European models with illuminated keypad entry (less common)

Frequent mistakes & best practices for code B1623 #

When addressing B1623, some common errors can slow down or complicate repairs. Here’s what to avoid, and what to do instead:

• Don’t assume the keypad itself is always defective; wiring or a blown fuse are often at fault.
• Don’t overlook corrosion in connectors—especially in regions with harsh weather.
• Don’t replace the BCM before thoroughly testing circuits and components.
• Do check service bulletins (TSBs) for known issues on your model.
• Do use a wiring diagram to trace the lamp output circuit for your vehicle.

Express FAQ for code B1623 #

Here are quick answers to the most common questions about B1623:

• Q: Will B1623 cause my keyless entry system to stop working?
  A: The keypad may still function for entry, but without backlighting it can be difficult to use at night. In rare cases, if the fault affects shared wiring, the keypad might not respond at all.
• Q: Can I fix B1623 myself?
  A: If you are comfortable with basic electrical testing and have access to a wiring diagram, you can check fuses, bulbs, and visible wiring. For advanced diagnostics (control module testing), seek professional assistance.