Code
B1C76
LAND ROVER
B — Body
Relay Coil Circuit relay of front wiper cleaner
Views:
UK: 4
EN: 8
RU: 5
AI status
Completed
Completed
100%
Causes
- Open or short in the relay coil wiring
- Corroded or loose relay socket/connector
- Faulty front wiper/washer relay (coil open or shorted)
- Blown fuse or poor fuse contact feeding the relay coil
- Faulty body control module (BCM) or relay driver transistor
- Water ingress or corrosion in connectors or module
Symptoms
- Front wipers or washer pump do not operate when commanded
- Intermittent or inconsistent front wiper/washer operation
- No audible relay click from wiper/washer relay when activated
- Related warning message or stored body electrical DTC (B1C76)
- Possible erratic operation of other circuits controlled by same module (if module fault)
What to check
- Read and record freeze-frame/live data and confirm B1C76 is current or historic using a scan tool
- Visual inspection of relay, relay socket, wiring harness, and connectors for corrosion, damage, or water ingress
- Check relevant fuses for continuity and proper seating
- Swap the suspect relay with an identical known-good relay (if available) to see if fault clears
- Backprobe relay socket to measure coil supply and control signals with switch operated
- Measure relay coil resistance on the relay (bench) or at the socket with relay removed
Signal parameters
- Coil resistance (typical): roughly 60–120 Ω (varies by relay design) — an open is infinite, short is very low (
- Activation supply voltage: battery voltage (~11–14 V) present across coil when relay is commanded
- Activation current: typically ~0.08–0.25 A depending on coil resistance
- Control method: often low-side switching by BCM (BCM sinks coil to ground) — control wire will be near battery voltage when off and pulled near 0 V when active
- Expected behavior: relay socket should show battery voltage on one coil terminal and a switching voltage on the other when the wiper/washer is commanded
Diagnostic algorithm
- Confirm the fault: Use a diagnostic scanner to read B1C76 and check if the code is current. Note any related codes.
- Visual inspection: Inspect relay, socket, wiring harness, connector seals, and related fuses for corrosion, damage, loose pins, or water intrusion.
- Check fuse: Verify continuity of the fuse supplying the relay coil and inspect fuse holder for corrosion or poor contact.
- Swap relay: If a matching relay is available in the fuse/relay box, swap it to see if the fault and operation change. If relay swap cures problem, replace relay.
- Measure at relay socket: With ignition on and wiper/washer command active, backprobe the relay coil terminals. Confirm battery feed on one terminal and a switching signal on the other. If no battery feed, trace fuse/power supply. If no switching signal, test BCM output.
- Measure coil resistance: Remove relay and measure coil resistance on the relay itself (bench). Compare to manufacturer spec. If open/short, replace relay.
- Wiring continuity: Check continuity from relay socket to BCM and to ground as applicable. Repair any open or shorted wiring, damaged insulation, or connector faults.
- Check for short to ground or battery: With relay removed, measure resistance from coil control wire to ground and to battery; look for unexpected shorts.
- Check BCM driver: If wiring, connector, fuse, and relay are good but the control signal is missing or abnormal, test the BCM output driver per manufacturer procedure. Consider module reprogramming or replacement only after verifying external circuit integrity.
- Re-test and clear codes: After repair, clear the code and cycle the system multiple times to verify the fault does not return and proper operation is restored.
Likely causes
- Relay coil open (internal failure) or shorted coil
- Broken/disconnected wire between BCM and relay coil (open circuit)
- Short to ground or battery on the coil feed or control wire
- Corroded relay socket terminals causing high resistance or intermittent contact
- Blown / poor fuse supplying the relay coil
- BCM output driver failed and not energizing or sinking the coil
Fault status
Status
Relay coil circuit fault — front wiper/washer relay (B1C76). Detected open/short or abnormal coil circuit current/voltage.
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
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