B1261

Code

Other B — Body

Solar Radiation Sensor Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 31 EN: 41 RU: 33

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Page language: EN

Causes

Damaged or chafed wiring shorting to chassis ground
Corroded, bent or pushed-back connector pins
Failed solar radiation sensor (internal short)
Aftermarket accessory or repair damaged the harness
Faulty body/climate control module (less common)
Water intrusion or contamination at the sensor/connector

Symptoms

DTC B1261 stored and MIL or warning indicator may be illuminated
Automatic climate control behaving incorrectly (overcooling/overheating)
Solar-related functions not responding or defaulting
Incorrect sunload readings in live data (very low or 0 V)
Intermittent operation if wiring is damaged and moves

What to check

Read and record freeze-frame and live data for solar sensor with a scan tool
Visual inspection of solar sensor, harness routing, and connector for damage/corrosion
Back-probe sensor signal and reference pins to measure voltage with ignition ON (key on, engine off)
Check continuity between sensor signal pin and vehicle ground with harness disconnected
Wiggle test harness while monitoring live data to reproduce problem
Inspect for water/moisture intrusion at sensor or inside dash (if sensor mounted there)

Signal parameters

Reference supply typically: ~5 V reference (confirm with model-specific data)
Sensor output (sunlight dependent): 0–5 V range; a short to ground typically reads near 0 V
With connector disconnected, continuity from signal pin to chassis ground should be open/infinite (no short)
Typical sensor impedance varies by design — consult vehicle manual; but a direct short will show near 0 Ω to ground

Diagnostic algorithm

Safety: Park vehicle, key off, and follow safe electrical procedures. Use a quality scan tool.
Read DTCs and freeze-frame; record live solar sensor voltage/value with ignition ON (do not start engine unless required by manufacturer).
Inspect sensor and harness: look for damaged insulation, pin corrosion, water entry, or signs of repair near the sensor and along the harness route.
With connector connected and key ON, back-probe the sensor signal and reference pins. Verify reference supply (usually ~5 V) and sensor output. A near 0 V output suggests a short to ground.
If signal reads near 0 V, turn ignition off, disconnect the sensor connector, and measure resistance between the harness signal pin and chassis ground. A low resistance indicates a short in the wiring or harness.
If harness shows a short, trace wiring toward the module, inspecting and repairing any chafed areas, pinched sections, or accessory junctions. Repair or replace wiring as required.
If harness is open (no short) but sensor output still low when connected, replace the solar radiation sensor and retest.
If wiring and sensor check good, verify module inputs and grounds. Check module connector pins and perform module-related tests per manufacturer procedure; replace module only if confirmed faulty.
After repairs, clear codes, verify proper sensor readings in live data across varying light conditions, and perform a functional test of automatic climate/related systems.

Likely causes

Wiring short to ground on the sensor signal or return
Failed sensor output stage internally shorted to ground
Poor or corroded connector making a low-resistance path to ground

Fault status

⚠️ Status

Solar Radiation Sensor Circuit Short To Ground — the control module detects the sensor signal is pulled to ground, preventing reliable solar input. Diagnostic checks should focus on sensor, connector, and wiring to ground.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours