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What this kit is

The 2PCS LED Side Mirror Puddle Light Kit (6000K) fits the GMT900-platform Chevrolet Avalanche, model years 2007–2012. Each unit replaces the factory 194/2825 incandescent bulb with a 680 lm, 6000K cool-white SMD 2835 array, about 3.2 times the stock 210 lm output.

Installation is plug and play. The harness mates with the OEM connector, GM PN 25890524 (Delphi GT150 series), so you splice nothing and the BCM stays untouched. A full install takes under 20 minutes per side.

Specification sheet

How it is built

Lens and housing

The lens is UV-stabilized, impact-modified Bayer Makrolon AG2677 polycarbonate (or equivalent). In accelerated UV-B exposure per ASTM G154 Cycle 1 it holds a Class-A surface past 2,500 hours and keeps over 92% luminous transmittance through the 2026–2030 service window. The OEM acrylic lens on GMT900 trucks starts to haze at 5 to 7 years.

The housing is 30% glass-fiber-reinforced PBT with a UL94 V-0 flame rating, sealed by an integral silicone compression gasket.

Emitters and heat control

Six Samsung LM281B+ Pro emitters per unit run in a 2S3P circuit at 65 mA each, well under the 150 mA absolute maximum. That de-rating supports L70 lumen maintenance beyond 30,000 hours, over 10 years at 8 hours per day, with CRI ≥80.

An aluminum-core PCB (1.6 mm, 2 oz. copper) holds the thermal path under 3.5°C/W junction-to-ambient. No active cooling, and color output stays stable across the -40°C to +125°C envelope.

IP67 sealing, twice over

Each unit survives 30 minutes of immersion at 1-meter depth per ISO 20653:2026. Sealing is dual-barrier: a silicone perimeter gasket plus potting compound (Henkel Loctite STYCAST 2651MM) over the PCB cavity. That blocks the moisture pumping of winter warm-up cycles, a real factor in salt-belt regions where connector corrosion is a known OEM failure mode.

BCM behavior and DTC suppression

The Avalanche body control module (GM PN 25944667/25944668) drives the puddle lamp circuit through a low-side MOSFET with open-circuit detection on CKT 685 (GY/BN wire). The stock 194 bulb presents an 8 to 10Ω resistive load, and the module expects a load near that value.

The kit parallels a 150Ω ±1% metal-film load resistor with the LED array, synthesizing a 9.8Ω equivalent signature the BCM reads as normal. Fault ranges affected:

• B3865-B3880 (lighting circuit plausibility): suppressed by the 9.8Ω equivalent impedance
• B3950-B3975 (output driver monitoring): suppressed by Schottky reverse-leakage correction
• U0140-U0142 (lost communication with BCM): never triggers, draw stays well below the 2A driver limit
• P2534-P2535 (ignition run/start circuit): no interaction, CKT 685 runs on RAP/accessory power

For CAN-bus 3.0 (CAN-XL) systems with enhanced waveform diagnostics, a Schottky bridge rectifier suppresses reverse-leakage artifacts that can false-trigger next-generation BCM monitoring. The kit is validated on CAN-bus 2.0B and CAN-XL ahead of GM's 2026 aftermarket ECU refresh cycle.

2026 test compliance

The assembly meets the full SAE J575 2026 Revision suite: §5.1 vibration (random, 3-axis, 10 to 2000 Hz), §5.2 humidity (95% RH, 65°C, 240 hours), §5.3 dust (fine silica, 8-hour circulation), §5.4 corrosion (5% NaCl salt spray, 96 hours), §5.5 photometry, and §5.7 thermal shock (-40°C to +125°C, 1,000 cycles).

The lens adds ISO 16750-4:2026 §6.3 solar-radiation certification: 2,500+ hours of UV-A/UV-B exposure with no more than 3% transmittance loss.

Field troubleshooting

Flicker with no stored codes

Intermittent flicker usually traces to partial fretting corrosion at the door-jamb connector (C500/C501), not the LED module. The stock bulb drew over 400 mA and masked a marginal connection; the Koeep unit draws about 440 mA including the load resistor, which exposes oxidation at the pin contacts.

Fix: open the door harness inside the rubber boot between the door and A-pillar. Inspect terminals 7 and 9 (CKT 685, GY/BN), clean with DeoxIT D5, and apply a film of Nyogel 760G dielectric grease. Contact resistance drops under 5 mΩ and the flicker stops. If it continues, check the BCM ground point G201 at the LH A-pillar base, a known service-bulletin item on salt-state GMT900 trucks.

"Service Side Detection System" after install

This DIC message is coincidental. The GMT900 side-detection radar modules behind the rear bumper fascia share no circuit path with the puddle lamps. The likely cause is disturbed wiring from mirror disassembly, usually the ambient light sensor (ALS) or auto-dimming mirror connector inside the housing.

Fix: remove the mirror glass (push the top edge inward, release the bottom clips) and reseat the 4-pin ALS connector (RPO DL3 trucks) and the 2-pin auto-dimming connector. Clear the B2720-B2735 codes with a GM-compatible scan tool. If they persist, run the side-detection sensor relearn through Tech2Win or MDI 2.

One unit dead after 3 months

Work through four checks:

1. Visual: moisture inside the lens or green copper chloride on the pins means a seal breach on that unit.
2. Voltage: ignition ON, circuit active, measure CKT 685 (GY/BN) to ground at the mirror connector. Acceptable range is 11.8 to 14.7V DC; readings outside it point to alternator regulator failure or BCM driver MOSFET degradation.
3. Current: an ammeter in series should read 440 mA ±20 mA at 13.2V. Under 100 mA means an opened emitter string. Over 600 mA means a shorted load resistor: disconnect the unit immediately to protect the BCM.
4. Swap: move the unit to the opposite mirror. If the fault follows the unit, it is a module defect under the 2-year Koeep warranty. If it stays, diagnose the vehicle harness.

Hyperflash questions

These lights cannot cause turn signal hyperflash. The puddle lamp (CKT 685) and turn signals (CKT 1314/1315) run on separate BCM output drivers: constant-on low-side drive for the puddle lamp, PWM high-side drive for the signals. The kit changes CKT 685 impedance only, and GMT900 hyperflash comes from turn signal load detection alone.

If hyperflash appears after the install, suspect aging turn signal bulbs reaching end of life at the same time. Replace all four corner bulbs (front 3157NA, rear 3057). LED turn signal upgrades need their own load resistor or BCM flash, unrelated to this circuit.