U0146 A module lost communication with gateway module A, which passes messages between the vehicle networks

Lost communication with gateway module A

U0146 in short

U0146 means a module stopped hearing from the gateway, the module that passes messages between the vehicle networks. Causes include gateway power or ground faults, harness damage, low battery voltage and software issues covered by GM and Ford bulletins. Symptoms range from dead remote features to warning lights and limp behaviour, so get it checked.

Modern vehicles have several data networks, and the gateway module routes messages between them and the diagnostic connector. U0146 sets when a module stops receiving the gateway messages it expects within a set time.

The effect depends on what the missing messages carry. On 2023 Ford trucks, U0146 in the telematics module comes with FordPass, remote start and remote lock not working. On Super Duty trucks it shows up in the ABS module with Hill Start Assist and parking brake warnings. On 2019-2020 Silverado and Sierra 1500, GM traced gauges sweeping and warning messages to an engine harness short.

Check bulletins and battery voltage first, then the gateway power, grounds and wiring.

Most likely causes

  1. Engine harness shorting at the left front cylinder head (2019-2020 Silverado 1500, Sierra 1500)

    Supported by vehicle data
    Why it ranks here
    GM PIT5713 lists U0146 among the codes when the engine harness shorts at the left front cylinder head, and Silverado owners report U0146 with U0100 and U0101.
    What would change this
    Rises on these trucks if the harness near the left cylinder head shows chafing.

  2. Telematics or gateway software (2023 F-150, Lightning, Bronco)

    Supported by vehicle data
    Why it ranks here
    Ford bulletins cover inoperative remote start, remote lock and FordPass features with U0146:09 in the telematics module.
    What would change this
    Rises if remote features are dead and U0146:09 is in the TCU.

  3. ABS-side communication concern on 2023-2025 Super Duty

    Supported by vehicle data
    Why it ranks here
    Ford SSMs describe U023A, U0159 and U0146 in the ABS module, with Hill Start Assist Unavailable or Parking Brake Limited Function messages.
    What would change this
    Rises on a Super Duty with these codes stored together in the ABS module.

  4. Loss of power or ground at the gateway

    Common general cause
    Why it ranks here
    The gateway cannot send messages without power and ground, and TAT lists this as a typical cause.
    What would change this
    Rises if the gateway does not answer a scan tool. Falls if its feeds and grounds test good.

  5. Low battery voltage

    Possible — needs testing
    Why it ranks here
    A 2025 Sierra dealer report showed U0146 together with U3003, a battery voltage code, and many other lost-communication codes.
    What would change this
    Rises if U3003 or other voltage codes are stored and the battery tests weak.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Scan every module and note which module stored U0146, any sub-code such as :09, and other codes present.

    Low riskTool: scan tool that reads all modules

  2. Have the 12-volt battery and charging system tested.

    Low risk

  3. Ask a dealer to check your VIN for bulletins or software updates that mention U0146.

    Low risk

  4. Have a shop check gateway power, grounds and network wiring.

    Best left to a shopTool: multimeter

    Warning:Probing module connectors can damage terminals; leave it to a technician.

Symptoms

  • Remote start, remote lock or app features not working
  • Hill Start Assist Unavailable or Parking Brake Limited Function message
  • Gauges sweeping or many warning messages
  • Loss of power or unexpected shifting Gets more serious: stop and have it checked.
  • Check engine light

How to fix

  1. Have the 12-volt battery tested and check that terminals and grounds are clean and tight.

  2. Write down every code from every module before anything is cleared.

  3. Ask a dealer whether your VIN has a bulletin or software update for U0146.

Parts and cost context

  • gateway module:Several U0146 cases are fixed by software or a harness repair, so check bulletins, battery and wiring before replacing the gateway. A new gateway needs programming. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chevrolet

  • 2019–2020 · Silverado 1500

    Supported by vehicle data

    GM PIT5713: engine harness short at the left cylinder head with U0146 among many U-codes; owners report U0146 with U0100 and U0101. Whether it is still current is not verified.

  • PIT5713Status unverified

    Engine harness shorting at left front cylinder head

    2019–2020silverado-1500 · issued · NHTSA 10165919

    Gauges sweeping, warning messages and MIL with many U-codes including U0146.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ford

  • 2023 · F-150

    Supported by vehicle data

    Ford SSM 51389 and TSB 23-2050: remote start, lock and FordPass features dead with U0146:09 (also Bronco). Whether they are still current is not verified.

  • 2023–2025 · F-250 Super Duty

    Supported by vehicle data

    Ford SSMs 51486, 53521 and 54160: U0146 with U023A and U0159 in the ABS module and Hill Start Assist warnings. Whether they are still current is not verified.

  • SSM 51389Status unverified

    Remote start and remote lock inoperative

    2023bronco, f-150 · issued · NHTSA 10232483

    U0146:09 in the telematics module and U2402 in the gateway; the repair was not read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • TSB 23-2050Status unverified

    FordPass features inoperative (F-150 Lightning)

    2023f-150 · issued · NHTSA 10232492

    U0146:09 in the TCU on early-build Lightning; the repair was not read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 51486Status unverified

    U023A, U0159, U0146 in ABS

    2023f-250, f-350, f-450-sd, f-550-sd · issued · NHTSA 10233769

    Image processing module A not communicating; the repair was not read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 53521Status unverified

    U023A, U0159, U0146 in ABS

    2023–2025f-250, f-350, f-450-sd, f-550-sd · issued · NHTSA 11016086

    Later Super Duty version; the repair was not read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • SSM 54160Status unverified

    Hill Start Assist Unavailable, Parking Brake Limited Function

    2023–2025f-250, f-350, f-450-sd, f-550-sd · issued · NHTSA 11022152

    U0151, U023A, U0159 and U0146 in the ABS module; the repair was not read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • U0100Lost communication with the engine or powertrain computer

    Shares causes Supported by vehicle data

    Silverado owners and GM PIT5713 show U0146 stored with U0100 when the network is disrupted.

  • U0101Lost communication with the transmission computer

    Shares causes Supported by vehicle data

    Silverado owners report U0146 with U0101 and U0100 together.

  • U0151Lost communication with the restraints (airbag) control module

    Shares causes Supported by vehicle data

    Ford SSM 54160 lists U0151 with U0146 in the Super Duty ABS module.

  • U3003Manufacturer code: on Ford, Lincoln, Mazda and Honda, the module that stored it saw its battery supply voltage outside the allowed range, usually too low

    Shares causes Possible — needs testing

    A 2025 Sierra dealer report showed U0146 with U3003 battery voltage.

All Module network (CAN bus) communication codes

Sources and review

  1. U0146: Lost communication with gateway module A — TAT (Technical Automotive Training) scan data codes
  2. GM PIT5713: engine harness shorting at left front cylinder head (2019-2020 Silverado 1500, Sierra 1500) — General Motors / NHTSA ,
  3. Ford SSM 51389: remote start and remote lock inoperative, U0146:09 (2023 F-150, Bronco) — Ford / NHTSA ,
  4. Ford SSM 54160: Hill Start Assist Unavailable, U0151/U023A/U0159/U0146 (2023-2025 Super Duty) — Ford / NHTSA ,
  5. NHTSA complaint ODI 11746696: 2025 GMC Sierra 1500 — NHTSA (owner complaint)
  6. NHTSA complaint ODI 11297440: 2020 Chevrolet Silverado 1500 — NHTSA (owner complaint)
  7. NHTSA complaint ODI 11749281: 2020 Chevrolet Silverado 1500 — NHTSA (owner complaint)
  8. NHTSA complaint ODI 11423686: 2019 Chevrolet Silverado 1500 — NHTSA (owner complaint)
  9. Ford TSB 23-2050: FordPass features inoperative, U0146 (2023 F-150 Lightning) — Ford / NHTSA ,
  10. Ford SSM 51486: U023A, U0159, U0146 in ABS after remote start (2023 Super Duty) — Ford / NHTSA ,
  11. Ford SSM 53521: U023A, U0159, U0146 in ABS (2023-2025 Super Duty) — Ford / NHTSA ,
Last reviewed
Written by
Saurabh K.
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