U1510 on 2015-2017 GMC Yukon: Active Grille Shutter Communication Fault Causes and Fixes

What's Unique About the 2015-2017 Gmc YUKON

While official Technical Service Bulletins (TSBs) like PIT5405C group U1510 with dozens of other codes caused by a poor Body Control Module (BCM) ground (G218), real-world data for the 2015-2017 Yukon shows this is misleading for an isolated U1510 code. The overwhelming majority of cases where U1510 appears alone are due to a direct failure of the active grille shutter assembly's internal motor, a common weak point on this GM truck platform. A Reddit thread with a user identifying as a Chevy dealer service advisor confirms this, stating they "sell several of them a month for this DTC" and that other issues like a thermostat would present different codes. The G218 ground issue is a valid, but separate, problem that typically causes a much wider array of severe electrical symptoms.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on.
• Active grille shutters may be stuck in the open or closed position.
• Remote start may be disabled.

Most Likely Causes

1. Failed Active Grille Shutter Assembly 🔴 High Probability The actuator motor/module integrated into the shutter assembly is a known high-failure part on this GM platform, often failing internally and causing a loss of communication on the LIN bus.
   How to confirm: Access the electrical connector for the shutter assembly. Using a multimeter, verify battery voltage on the power wire (typically violet/blue) and a good ground on the ground wire (black). Then, check the LIN bus signal wire (typically light green/violet); if power and ground are good but the signal is a flat line (stuck at battery voltage) instead of a varying voltage or square wave, the shutter assembly is faulty.
   Typical fix: Replace the entire active grille shutter assembly. The actuator motor is not sold separately. 🎬 See this walkthrough for replacing the entire shutter assembly. Be sure to transfer the ambient air temperature sensor from the old assembly to the new one.
   Est. part cost: $200-$450

Rare But Worth Checking

• Poor Body Control Module (BCM) Ground at G218: This is a plausible cause only if U1510 is accompanied by a wide range of other communication codes (like U0073, U0140, etc.) and severe symptoms like the instrument panel, radio, or HVAC going blank, engine stalling, or loss of power steering, as described in TSB PIT5405C. For an isolated U1510, this is highly unlikely.
• Damaged Wiring Harness: Physical damage to the wires running from the ECM to the grille shutter connector can cause a loss of communication. This is worth checking if the shutter assembly has been recently replaced and the code returns, or if there is visible damage to the front of the vehicle.
• Low Battery Voltage: Weak or failing batteries can cause random communication codes to appear across various modules. TSB PIT5405C mentions checking battery health and cable connections as part of a comprehensive diagnostic for electrical issues. If you've recently needed a jump start, this could be a temporary, non-critical code.

Diagnosis Steps

1. Read all fault codes from all vehicle modules with a capable OBD-II scanner. Note if U1510 is the only code or if many other communication codes are present.
2. If U1510 is the primary or only code, proceed with diagnosing the active grille shutters.
3. Remove the upper radiator air deflector (held in by plastic clips) to gain access to the top of the grille shutter assembly and its electrical connector.
4. Disconnect the electrical connector. Inspect for corrosion or damage.
5. With the key on, use a multimeter to test for battery voltage at the power pin (violet/blue) and continuity to ground at the ground pin (black) on the harness side of the connector.
6. If power and ground are good, reconnect the connector and back-probe the LIN bus signal wire (light green/violet). With the engine running, the voltage should vary or show a square-wave pattern on an oscilloscope. If the voltage is static (e.g., stuck at 12V), the shutter assembly has failed.
7. If power or ground is missing, trace the wiring back towards the fuse block (Fuse F46 in the underhood block) and ECM to find the fault.
8. If many other electrical codes and symptoms are present, locate and inspect the BCM ground G218. It is located behind the driver's side lower dash panel, near the A-pillar. Per TSB PIT5405C, ensure the nut is tight and that the dash insulation material is not trapped under the ground terminal, which can cause a poor connection.
9. Before installing the new shutter assembly, remember to transfer the ambient air temperature sensor from the old unit 🎬 Watch: A quick guide to fixing the U1510 code. to the new one.

Parts You'll Likely Need

• Active Grille Shutter Assembly (OEM #84378163 (superseded by 85043806)) — This is the direct cause of an isolated U1510 code. The internal actuator fails, and the entire assembly must be replaced.
  Trusted brands: ACDelco (GM Genuine), Dorman (e.g., 601-377), Autopart Premium
  OEM price range: $350-$450
  Aftermarket price range: $180-$300

Related Codes That Often Appear With This One

• U0073 — If the root cause is a major electrical issue like the G218 ground fault, multiple communication codes affecting different modules will appear together.
• U0140 — Like U0073, this indicates a broader network communication problem, often pointing towards a systemic issue like a bad ground rather than a single failed component.

Technical Service Bulletins (TSBs) & Recalls

• PIT5405C: Documents numerous electrical issues and DTCs, including U1510, that can be caused by a poor BCM ground at G218, a shorted starter cable, or loose battery connections. It describes a wide array of symptoms like stalling, blank screens, and power steering loss.
• PIT5405B: An earlier version of the same bulletin, also pointing to the G218 ground as a source of various electrical problems. [Bulletin #PIT5405B]

Platform-Specific Known Issues

• The actuator motor within the active grille shutter assembly is a common failure point on 2015-2017 GMC Yukons and related GM K2XX platform vehicles.
• TSB PIT5405C documents a separate issue where a poor BCM ground at location G218 can cause a multitude of communication codes, including U1510. Symptoms are widespread and severe, including stalling, blank instrument clusters, and loss of power steering. This ground should only be the primary suspect if symptoms go far beyond just a check engine light for U1510.

Mechanic-Grade Diagnostic Values

• LIN Bus Voltage (at rest, no communication) — expected: ~12V (system voltage). Failure: Voltage significantly lower than system voltage.
• LIN Bus Voltage (active communication, using oscilloscope) — expected: Square wave toggling between ~1.0V and ~12V (system voltage).. Failure: A steady, flat-line voltage (e.g., stuck at 12V or 0V) indicates a fault in the module or wiring.
• Active Grille Shutter Connector Pin 1 (Violet/Blue wire) — expected: Battery Voltage (12V+) with key on.. Failure: 0V indicates a blown fuse (F46 in underhood fuse block) or an open in the power wire.
• Active Grille Shutter Connector Pin 4 (Black wire) — expected: Near 0V (good ground).. Failure: Voltage present or high resistance to ground indicates a bad ground wire.
• Active Grille Shutter Connector Pin 3 (Light Green/Violet wire) — expected: Varying voltage between 10V-12V with a multimeter, or a square wave on an oscilloscope.. Failure: Voltage stuck steady at battery voltage indicates an internally shorted shutter module.

Scan Tool Commands That Help

• GDS2 (or capable high-end scanner): Active Grille Shutter Test / Output Controls — After installing a new shutter assembly or to verify functionality. This command allows the technician to manually command the shutters to open (100%) and close (0%) to confirm the new part is working correctly and communicating with the ECM.
• OBD-II Scanner: Clear Codes / Erase DTCs — After replacing the shutter assembly, the code needs to be cleared. In most documented cases, no special 'relearn' or 'initialization' procedure is required beyond clearing the code. The check engine light should stay off after cycling the ignition.

Wiring & Ground Locations

• Active Grille Shutter Connector — Behind the front grille, typically on the upper passenger side of the shutter assembly.. This is the primary test point. Pin 1 (Violet/Blue) is power, Pin 4 (Black) is ground, and Pin 3 (Light Green/Violet) is the LIN bus communication wire to the ECM. Testing these three wires confirms if the fault is in the shutter assembly or the vehicle wiring.
• G218 — Behind the driver's side lower dash/kick panel, near the A-pillar. It is a ground stud on the body.. This is the BCM ground referenced in TSB PIT5405C. A poor connection here, often due to trapped dash insulation, causes widespread electrical issues and multiple communication codes, including U1510. It is not a likely cause for an isolated U1510 code.
• Fuse F46 — In the underhood fuse block (X50A).. This fuse supplies power to the active grille shutter assembly. If there is no power at Pin 1 of the shutter connector, this fuse should be checked.

Real Owner Repair Stories

• Reddit user in r/gmcsierra (2017 GMC Sierra Denali 1500 6.2L) — Check engine light with code U1510, active shutters would not open.
  ❌ Tried (didn't work) Pulling a fuse to reset the system.
  ✅ What actually fixed it After replacing the shutter assembly, the code remained. The final fix was to disconnect the negative battery terminal for 10 minutes to force a full system reset, which cleared the code and restored shutter function.
• Reddit user in r/Silverado (2018 Chevy Silverado 5.3L) — Check engine light, remote start disabled, code U1510.
  ❌ Tried (didn't work) Initial diagnosis pointed to a possible wiring issue.
  ✅ What actually fixed it The user traced the wiring harness and found a broken/corroded LIN bus communication wire near the first auxiliary connector by the driver's side headlight. Repairing the single broken wire with a scotch lock connector resolved the U1510 code without replacing the shutter assembly.
• ScannerDanner Forum user (2018 Silverado High Country 5.3) — Code U1510, shutters locked open.
  ❌ Tried (didn't work) Replacing the original shutter assembly with an aftermarket Dorman part did not fix the issue; the new part was also unresponsive.
  ✅ What actually fixed it The user was advised that the diagnostic readings (good power, good ground, fluctuating voltage on LIN wire) strongly pointed to a failed module, and the aftermarket part could be faulty out of the box. The final resolution was implied to be replacing the unit with an OEM part. This highlights potential issues with non-OEM replacements for this specific component.

OEM Part Supersession History

• 84046019 → 84378163 — Standard part revision by manufacturer.
• 84378163 → 85043806 — Standard part revision by manufacturer.
  Heads up: 85043806 is the current OEM replacement for the 2015-2017 model years.