B1C0C

Code

Generic B — Body

Keyless entry receiver circuit fault

Brand: Generic

Type: B — Body

Views: UK: 17 EN: 32 RU: 19

AI status

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ready

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Page language: EN

Causes

Blown fuse or open power supply to receiver
Open or high-resistance ground at receiver/module
Corroded, loose or damaged receiver module connector or antenna coax
Damaged or disconnected antenna or antenna amplifier
Faulty keyless-entry/remote receiver module or body control module (BCM)
Defective or weak key fob battery or transmitter

Symptoms

Remote keyless entry (lock/unlock/trunk) inoperative or intermittent
Reduced remote range or need to be very close to vehicle
Multiple or repeating keyless entry fault codes on scan tool
Doors lock/unlock unexpectedly or not respond to remotes
No RF activity detected when pressing key fob (measurable with RF sniffer)
Related body-control or immobilizer warnings, or loss of remote start functionality

What to check

Retrieve and record all stored codes and freeze frame with a scan tool
Inspect vehicle battery voltage (should be ~12.4–12.8 V at rest, 13.5–14.8 V while charging)
Visually inspect fuses and fusible links for the receiver/BCM circuits
Visually inspect receiver and antenna connectors for corrosion, water, bent pins or damage
Check key fob battery voltage (typically ~3.0 V for CR2032) and try a known-good spare fob
Wiggle test wiring harnesses and connectors while watching live data or while operating remote

Signal parameters

Receiver supply voltage: ~9–16 V (nominal 12 V system) with engine off and with starter cranking; no rapid drop or intermittent loss
Ground resistance:
Key fob battery: ~2.8–3.2 V (CR2032 typical); below ~2.4 V may cause weak transmission
RF carrier frequency: vehicle dependent — commonly 315 MHz (NA) or 433/434 MHz (EU/ROW) — a functioning transmitter produces bursts at correct carrier frequency
RF signal amplitude: depends on antenna/receiver; use RF sniffer or spectrum analyzer for expected field strength near vehicle with key fob pressed
Data pulses/modulation: ASK/FSK bursts matching manufacturer timing when fob button pressed

Diagnostic algorithm

Safety: place vehicle in park, apply parking brake, remove ignition key. Use appropriate anti-static and battery-disconnect procedures if removing modules.
Scan and record all DTCs and freeze frame; clear codes and attempt to re-create the fault to confirm persistence.
Verify basic power/ground: measure battery voltage and check fuse(s) for receiver/BCM circuits. Replace blown fuse only after diagnosing cause.
Test key fob: check battery voltage, verify operation with spare known-good fob or use dealer/tester to verify transmitter output. If fob fails, replace battery or fob before vehicle-side repairs.
Visual inspection: inspect receiver, antenna and associated wiring for damage, corrosion, water ingress, pin damage or crushed coax. Repair or reseal as required.
Verify supply: backprobing receiver power pin with keyless system activated; confirm steady 9–16 V and no dropouts while operating remote.
Verify ground continuity: measure between receiver ground pin and chassis; repair any high-resistance ground.
Antenna/receiver continuity: measure antenna feed continuity (where applicable) and check for short to shield or open conductor. Replace antenna if open or physically damaged.
RF verification: use an RF sniffer/spectrum analyzer to confirm carrier bursts at expected frequency and modulation when pressing the fob near vehicle. If receiver sees no RF but fob transmits, suspect vehicle antenna/receiver.
Check communications: use scan tool to monitor CAN/LIN messages and module responses while operating remote; look for comm timeouts or repeated errors.
Wiggle-test harnesses and connectors while monitoring live data or operating the remote to locate intermittent faults.
If wiring and external components check good, attempt module reprogramming/reflash if manufacturer procedure indicates; perform module reset if applicable.

Likely causes

Loose or corroded connector on the receiver or antenna
Failed receiver module or BCM input stage
Broken/shorted antenna feed or damaged antenna element
Weak key fob battery or damaged key fob transmitter
Blown fuse or poor chassis/battery ground near receiver
Intermittent wiring fault in harness to the receiver module

Fault status

⚠️ Status

Keyless entry receiver circuit fault — receiver detects power/ground, antenna or internal circuit failure, or invalid/absent RF/data from remote. May be intermittent.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours