B2735

Code

Generic B — Body

Remote Keyless Entry Transmitter Not Programmed

Brand: Generic

Type: B — Body

Views: UK: 0 EN: 0 RU: 0

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

New or replacement transmitter not programmed to vehicle
Transmitter battery dead or weak
Transmitter damaged (water, impact, circuit failure)
Vehicle receiver/BCM/immobilizer lost memory or faulted
Rolling code or encryption mismatch after replacement
Receiver antenna/ wiring fault or poor grounding

Symptoms

Keyless entry buttons do not lock/unlock doors
No audible/visual confirmation (horn/flash) when pressing fob
Some keys work while one or more do not
Push-button start does not recognize remote (if applicable)
Security/immobilizer warning lamp may be illuminated or flash

What to check

Verify transmitter battery voltage with a multimeter (expect ~3.0 V for CR2032 style)
Try a spare/transponder known to be programmed to the vehicle
Observe LED on fob (if equipped) or use RF sniffer to check for transmission
Scan vehicle for body module/immobilizer fault codes and key memory entries
Inspect key fob for physical damage and clean contact pads
Check vehicle battery voltage and ground connections

Signal parameters

Typical RF frequency: 315 MHz (North America) or 433/868 MHz (other regions) depending on vehicle
Transmitter battery voltage: typically ~3.0 V (coin cell) — low voltage reduces range or prevents transmission
Signal type: ASK/OOK or FSK with rolling code / encrypted identifier
Receive sensitivity and packet structure vary by manufacturer; encryption/rolling code mismatch prevents recognition

Diagnostic algorithm

Confirm symptom with customer and identify which transmitter(s) fail.
Measure transmitter battery voltage; replace battery and re-test transmitter operation at close range.
If available, use a second known-good programmed transmitter to confirm vehicle receiver still accepts keys.
Use a scan tool capable of reading the body/BCM/immobilizer to check for key ID list and related DTCs; record any codes.
Attempt to enroll/program the transmitter following the manufacturer's procedure (scan tool or manual on-vehicle procedure).
If programming fails, check vehicle battery voltage and grounds, then inspect receiver antenna wiring and module connectors for damage or corrosion.
If module appears faulty or lost memory, check for service bulletins and verify replacement/module reprogramming requirements before replacing.
If transmitter does not transmit (no RF) after battery replacement, suspect internal transmitter failure — repair or replace the fob.
After successful programming, verify all transmitter functions and confirm that vehicle security/immobilizer status is normal.

Likely causes

Key fob battery dead (most common)
Transmitter never enrolled after replacement
Vehicle lost learned keys due to module replacement or battery disconnect
Damaged transmitter RF circuit or button contacts
Programming procedure not completed or incorrect tool used

Fault status

⚠️ Status

Remote keyless entry transmitter ID not stored or not recognized by vehicle receiver/immobilizer. Transmitter may be unprogrammed, defective, or communication with body module lost.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours