U1510 is a LIN bus communication code: a control module reported that it stopped hearing from a device on the Local Interconnect Network. On most Chevrolet and GMC trucks and SUVs the device named is the active grille shutter actuator — but GM's own bulletin warns in the same sentence that seven other modules on that bus can set the identical code. That single line is why so many grille shutters get replaced without fixing anything.
Jump to a section: What U1510 means · The two-part code form · Symptoms · Causes and how to confirm each · Affected vehicles · How it's diagnosed · Parts, labor and cost · Service bulletins · What other pages get wrong · FAQ
What U1510 Means
U1510 sits in GM's U15xx block, which covers "lost communication with a smart device" on the LIN bus. The LIN (Local Interconnect Network) is a slow, single-wire network GM uses for components that don't need the speed of the main CAN bus — grille shutters, some HVAC controls, the battery monitor, the park actuator. GM's master LIN document puts it plainly:
"If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device."
— GM PIT5698D, LIN Bus Diagnostic Information, 26 September 2023, applicable to all GM brands 2013–2024
There is no single universal definition, because the description you see on the scan tool depends on which module reported the fault. Three variants are documented in GM bulletins:
| Reporting module | GM's wording | Where it's documented |
|---|---|---|
| Engine Control Module (K20) | Lost Communication with M96 Active Grille Air Shutter Actuator / M60A Active Grille Air Shutter 1 Motor Module on LIN Bus — "There are 7 other modules on the BUS that may set this DTC" | Bulletin 15-NA-087 |
| HVAC Control Module (K33) | Set for a loss of communication with the A20 Radio / HVAC controls on the LIN Bus | Bulletin PIC5965 / PIC5965C |
| Instrument Panel Cluster | Steering wheel controls inoperative and/or DTC U1510 set (cluster software anomaly) | Bulletin 17-NA-169 |
So the honest reading of U1510 is: something on the LIN bus went quiet. Which something depends on the vehicle and on which module logged it. Read the full description off the scan tool rather than assuming.
The Two-Part Code Form: U1510-XX
GM normally writes trouble codes in two parts — a five-character base code, then a two-digit failure type byte after a dash that narrows down the fault mode. For U1510, no GM-documented sub-types were found.
Every GM bulletin that mentions this code — 15-NA-087, 16-NA-051, 17-NA-102, 17-NA-169, 21-NA-149, PIC5965, PIC5965C, PIT5383B, PIT5405A, PIT5698D — writes it as bare U1510, with no dash suffix anywhere. If your scan tool shows U1510-00, the 00 is the generic SAE "no sub type information" byte, which is what you would expect on a communication code that carries no further circuit detail.
Several sites publish a table of 32 sub-types for U1510 (-00 through -1F, with meanings like "short to battery voltage" and "control module fault"). That table is a generic template applied automatically to every code on those sites. It is not U1510 documentation, and none of those pairings could be traced to a GM source. Don't diagnose from it.
Symptoms of U1510
What you actually notice depends on which device dropped off the bus. From GM's bulletins:
- Stop/Start path: the Stop/Start system stops working, a "Stop/Start System Disabled" message appears on the driver information centre, and the check engine light comes on.
- Grille shutter path: check engine light on, shutters inoperative — and frequently no drivability symptom at all. The truck drives normally; only the light tells you anything is wrong.
- HVAC path: blower motor or indicators inoperative, blower runs but speed can't be adjusted, or the A/C doesn't blow cold enough.
- Bolt EV: steering wheel controls stop responding.
- Harness chafing path: a scatter of unrelated faults — no start, no crank, rough running, reduced engine power, erratic speedometer, blown fuses, gauge sweep, stalling.
If U1510 shows up alongside a pile of unrelated body and chassis codes, stop treating it as a grille shutter problem. That pattern points at a ground fault or a chafed harness.
Common Causes of U1510 — and How to Confirm Each One
| Cause | How to confirm it | How common |
|---|---|---|
| Water intrusion and corrosion at the active grille shutter connector | GM 15-NA-087 makes this a dedicated inspection step. Unplug the in-line connector at the actuator and look for moisture and green or white corrosion on the pins | Most common on trucks and SUVs |
| Wiring harness damage — chafe-through, high resistance, loose connector | Inspect the engine harness at the ECM bracket, generator bracket and stud contact points. GM 17-NA-102 says explicitly: do not replace the front object alarm harness until the shutters have been inspected, diagnosed and tested | High |
| Failed grille shutter actuator or motor module | Reference-voltage test per PIT5698D. Disconnect the master and every other smart device, then confirm the suspect device outputs its own steady 12V reference. The actuator is not serviced separately — the shutter assembly is replaced complete | Moderate, and consistently over-diagnosed |
| Snow or ice obstructing the shutters | GM 17-NA-102 step 1: verify nothing is obstructing the shutters. 16-NA-051 tells the technician to advise the owner the light clears on its own once the shutters work again, with no effect on reliability | Seasonally common — and GM's documented response is to sell no parts at all |
| Corrosion at ambient air temperature sensor connectors (Malibu, LaCrosse) | Inspect connectors B9, M60B and X119. GM 16-NA-051 maps each finding to a different repair | Platform-specific |
| Poor BCM ground at G218, or a shorted B+ cable at the starter | Per PIT5405A: check whether the dash insulator mat is trapped between the ground eyelet and the body stud; check the B+ cable against the starter heat shield; voltage-drop test both battery cables while cranking | Lower — but this is the one to check when U1510 arrives with a scatter of unrelated codes |
| Failed battery monitor module (Stop/Start vehicles) | GM makes this the last step, after a battery test and a full LIN connector inspection. A parasitic draw over ~100 mA stops the 4-hour learn completing; state of charge at or below 65% disables Stop/Start on its own | Low as a cause of U1510 specifically |
| Module software calibration | Match the VIN and build date against 17-NA-169 (Bolt EV cluster), PIC5965C (Camaro HVAC) or PIT5383B (HVAC module) | Low overall, near-certain inside those VIN ranges |
Vehicles Documented in GM Bulletins for U1510
| Bulletin | Concern | Vehicles and years |
|---|---|---|
| 15-NA-087 (Oct 2022) | Stop/Start inhibited, MIL on | Buick Enclave 2018–2023, Encore 2016–2022, Envision 2016–2022, LaCrosse 2017–2019 · Cadillac ATS 2017–2019, CT6 2016–2023, XT4 2019, XT5 2017–2023, XT6 2020 · Chevrolet Bolt EV 2021–2023, Cruze 2016–2019, Equinox 2018–2022, Malibu 2017–2022, Silverado 1500 2019–2022, Traverse 2018–2023 · GMC Acadia 2017–2023, Sierra 1500 2019–2022, Terrain 2018–2023 |
| 16-NA-051 (Dec 2017) | Active shutters inoperative | Buick LaCrosse 2017–2018 · Chevrolet Malibu (VIN Z) 2016–2018 |
| 17-NA-102 (Apr 2020) | Active shutters inoperative | Cadillac ATS and CTS 2016–2017 |
| 17-NA-169 (May 2017) | Steering wheel controls inoperative | Chevrolet Bolt EV 2017 |
| 21-NA-149 (Nov 2021, rev. Aug 2024) | Engine wire harness chafing | Cadillac Escalade 2021–2023 · Chevrolet Silverado 1500 2019–2023, Suburban and Tahoe 2021–2023 · GMC Sierra 1500 2019–2023, Yukon 2021–2023 |
| PIT5405A (Nov 2015) | Ground fault / B+ short | Chevrolet Silverado 1500 2014–2016, Suburban and Tahoe 2015–2016 · GMC Sierra 2014–2016, Yukon 2015–2016 · Cadillac Escalade 2015–2016 |
| PIT5698D (Sep 2023) | LIN bus diagnostic reference | All GM brands and models 2013–2024 |
Worth knowing: no GM bulletin names U1510 on 2014–2018 K2XX Silverado and Sierra 1500 specifically, even though owner reports for those trucks are common. A federal class action does name U1510 as the code behind a defective grille shutter on a 2017 GMC Sierra 1500, covering 2017–2019 Silverado, Suburban, Sierra, Yukon and Escalade — but that is an allegation in litigation, not GM documentation.
How U1510 Is Diagnosed
A generic code reader cannot diagnose this. GM's own words explain why:
"LIN buses are not wired to the DLC, thus the scan tool does not communicate directly on a LIN bus. The scan tool will communicate with the master controller of the LIN bus... in order to command outputs or read parameters from the smart device(s)."
— GM PIT5698D
You need a bidirectional tool that can address the specific master module and command its LIN outputs — GM GDS2/MDI or a full-system aftermarket equivalent. You also need a meter. GM specifies a Fluke 87 set to peak min/max with 1 ms record; without the peak setting the meter misses the true minimum and typically reads 7–9 volts, which makes a perfectly healthy bus look broken. Fit a battery maintainer first, because LIN operates between 1 and 12 volts and reads wrong at low system voltage.
Reference values, from PIT5698D: at rest the bus sits at a steady ~12V. Communicating, at peak min/max, it swings between about 12V maximum and 1V minimum. It never reaches full system voltage and never reaches ground. Full system voltage with no toggling means a short to power; no voltage at all means an open or a short to ground.
- Run the Diagnostic System Check — Vehicle, and work the codes in the order it gives you.
- Identify which module set U1510 and which device it names. Do not assume grille shutter. Seven other modules can set it.
- Inspect physically before testing electrically: nothing obstructing the shutters, no water in the actuator connector, LIN connectors clean and secure, unused connector cavities properly sealed. Check terminal tension with the correct test probes and flex the harness to provoke an intermittent.
- Cross-check the other devices on the same bus. If everything is down, suspect the master or the wire; if only one is down, suspect that device or its branch.
- Test the master's reference voltage: master connected, smart devices disconnected, ignition on, measure at the device connector for the toggling reference.
- Test the device's reference voltage: suspect device connected, master and all other smart devices disconnected, measure at the master connector for a steady ~12V.
- If voltage is present, verify the part number. GM warns directly that smart device part numbers change year to year and look similar — a same-looking, wrong-year shutter will set this code.
- Escalate per bulletin: on Stop/Start vehicles, battery test then battery monitor module; on matching VIN ranges, reprogram the indicated module.
Parts, Labor Time and Cost
Every part number below is from a GM bulletin or an official GM parts catalogue. Labor times are GM Labor Operation codes read from the bulletins themselves.
| Repair | GM part number | Part cost | GM labor operation | Labor time |
|---|---|---|---|---|
| Active grille shutter assembly, 2017–2019 Silverado / Sierra 1500 | 85043807 (supersedes 84363184 and 23300225) | $325–$334 | No GM book time published for this operation | |
| Active grille shutter assembly, 2019–2022 Silverado / Sierra 1500 | 85797923 (supersedes 84652494) | ~$220 | No GM book time published | |
| Active shutter operation validation (ATS / CTS) | — | — | 1480778 | 0.3 hr |
| Front object alarm harness test and replace (ATS / CTS) | Refer to EPC — no public number | — | — | 1.7 hr |
| Ambient air temp sensor harness (Malibu / LaCrosse) | 23258243 harness, 13504371 connector kit | — | 5480328 | 0.5 hr |
| Engine harness chafing inspect and repair | Kent 1089482 tape, 84389052 ECM bracket clip, 84820678 / 84826758 Kevlar sleeves, 13596790 generator bracket clip | — | 5480728 | 1.2 hr |
| Wrap and secure engine wire harness | Kent 1089482 tape, 84820678 / 84826758 sleeves | — | 5486188 | 1.3 hr |
| Battery monitor module (Stop/Start) | Refer to EPC — no public number | — | 4040070 | Published time |
| HVAC control module reprogram | Software only | — | 2810015 | Published time |
| Instrument cluster reprogram (Bolt EV) | Software only | — | 2810195 | Published time |
A real-world total, for scale. A dealer invoice quoted in the federal class action for a 2017 GMC Sierra 1500 diagnosed with U1510 came to roughly $902: $195 diagnostic, $375.71 for the part, and $331.50 labor at 1.7 hours. That is the number to weigh against the fifteen minutes it takes to unplug the shutter connector and look for corrosion first.
Order by VIN. Those supersession chains are live and the parts look nearly identical between years — which is precisely the failure PIT5698D warns about.
GM Service Bulletins That Name U1510
These are real bulletins, filed with NHTSA and verified to contain this code. Take the number to your dealer.
| Bulletin | Date | Subject |
|---|---|---|
| 15-NA-087 | May 2017, rev. Feb 2019 and Oct 2022 | Stop/Start system inhibited with MIL illuminated |
| 16-NA-051 | Jun 2016, rev. Dec 2017 | Active shutters inoperative, MIL illuminated |
| 17-NA-102 | Apr 2020 | Active shutters inoperative, MIL illuminated |
| 17-NA-169 | May 2017 | Steering wheel controls inoperative and/or U1510 set |
| 21-NA-149 | Nov 2021, rev. Aug 2024 | Engine wire harness chafing — various DTCs |
| PIC5965C | May 2015 | Heating and cooling concerns with HVAC control module U1510 |
| PIT5383B | Sep 2015 | HVAC blower, heated seats, dead battery — reprogram K33 |
| PIT5405A | Nov 2015 | Reduced power steering assist, stall, blank IPC / radio / HVAC |
| PIT5698D | Sep 2023 | LIN bus diagnostic information — all GM 2013–2024 |
There is no special coverage, warranty extension or recall for U1510. We searched NHTSA's bulletin archive from 2013 to 2026 and found none. If a page tells you the grille shutter is covered by an emissions warranty extension, check the document — the "Active Grille Shutter Emission Warranty Extension" that circulates in search results is Nissan's, covering 2019–2020 Altima, and has nothing to do with GM. Whether GM should cover these repairs under emissions warranty is currently the subject of an unresolved class action, not settled policy.
What Most U1510 Pages Get Wrong
This code has an unusually bad footprint online, and it costs people money. Three things to watch for:
- The 32-row sub-type table. Several sites list U1510-00 through U1510-1F with specific meanings. It's a generic template stamped onto every code on those sites. No GM source documents any of it.
- The "A11 Radio" definition. Widely republished, traceable to no GM document. GM's own bulletin puts the HVAC variant in the K33 HVAC control module, not the radio.
- "U1510 means replace the grille shutter." GM's bulletin says seven other modules can set it, tells technicians to check for water in the connector first, and in the snow-and-ice case tells them to sell no parts at all. Shutters get replaced against this code constantly, and a good share of them were fine.
Frequently Asked Questions
Is U1510 serious?
Usually not urgent. On the grille shutter path most owners report no drivability symptom at all beyond the check engine light — the shutters simply stop modulating airflow. Worth diagnosing, because the light will hide anything else that comes along, but it is not a stop-driving code. The exception is when U1510 appears alongside a scatter of other faults, which points at a harness or ground problem that can cause stalling and no-starts.
Does U1510 always mean the active grille shutter is bad?
No, and this is the single most expensive misconception about this code. GM's own bulletin says in the code description that seven other modules on the same LIN bus can set it. Water in the shutter connector, a chafed harness and a poor ground are all documented causes, and GM tells technicians to inspect all three before condemning the shutter.
What does the -00 mean in U1510-00?
No GM-documented sub-types exist for U1510. Every GM bulletin writes it as bare U1510. A -00 on your scan tool is the generic "no sub type information" byte, which is normal for a communication code.
Can I fix U1510 myself?
The inspection part, yes, and it's worth doing. Unplugging the grille shutter connector to look for water and corroded pins costs nothing and is GM's own first step. Clearing snow and ice off the shutters is free. The electrical diagnosis is not a DIY job — the LIN bus isn't wired to the diagnostic port, so you need a bidirectional scan tool that can address the master module, plus a meter set to peak min/max.
Will clearing the code make it go away permanently?
Only if the underlying condition is genuinely gone. In one documented case GM explicitly expects it to clear itself: when snow or ice jammed the shutters, the light goes out once they work again. In every other case the code returns, because clearing a code doesn't repair a corroded pin or a chafed wire.
How much does a U1510 repair cost?
A grille shutter assembly runs roughly $220–$334 for the GM part depending on year. A dealer invoice from a 2017 Sierra came to about $902 all in, including a $195 diagnostic fee and 1.7 hours of labor. If the actual fault is a corroded connector or a chafed wire, the repair is a fraction of that — which is the argument for inspecting before ordering.
Does U1510 mean the same thing on every GM vehicle?
No. It always means "lost communication with a device on the LIN bus," but the device it names changes by platform. On trucks it usually names the grille shutter actuator. On a 2014 Camaro it's the HVAC control module losing the radio controls. On a 2017 Bolt EV it's the instrument cluster and the steering wheel controls. Read the full description off the tool.
Why did my grille shutter get replaced and the code came back?
Two common reasons, both documented by GM. Either the real fault was upstream — a chafed harness or a high-resistance connection, which is why GM warns technicians not to replace the harness or the shutter until the shutters have actually been tested — or the replacement part is the wrong year. GM warns that smart device part numbers change year to year and look similar, and a wrong-year part will set this code straight back.
Shop the Parts Mentioned
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KONNWEI KW850 OBD2 Scanner — $83.11, retrieves generic (P0, P2, P3, U0) and manufacturer-specific (P1, P3, U1) codes, so it reads network codes like this one. Live data with graphing, freeze frame, O2 and EVAP tests, battery voltage check, and a built-in DTC lookup library. Engine-system coverage only — it does not read ABS or airbag modules.
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VDIAGTOOL BT500 Battery Tester — $57.53, tests battery health, cranking and charging on 6V/12V/24V systems with ripple analysis and a voltage waveform — rules out low system voltage, a common trigger for spurious module-communication codes.
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Battery Terminal Cleaning Brush — useful for cleaning corroded grounds contributing to communication faults.
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ACDelco Gold Negative Battery Cable — for replacing a corroded ground or battery connection.
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95-Piece Mechanics Tool Set (Metric & SAE) — covers access to dash grounds and connectors.