U0422 on 2017 Chevrolet Silverado: Invalid BCM Data Causes and Fixes

What's Unique About the 2017-2017 Chevrolet SILVERADO

While U0422 generically points to the Body Control Module (BCM), on 2017 GM K2XX platform trucks like the Silverado, the issue is very frequently traced back to the Serial Data Gateway Module (SDGM). This module acts as a central hub for network communications. A known weakness is the terminal connections at the SDGM's X1 and X2 connectors, which can become loose and disrupt communication, leading other modules to incorrectly blame the BCM. This specific failure pattern is well-documented by GM in multiple technical service bulletins, including PIT5586B, PIT5586E, and PIT5586G.

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
• Erratic instrument cluster behavior (gauges dropping to zero, flickering 🎬 Watch: Troubleshooting a flickering instrument cluster and related fuses.)
• Warning lights and chimes activating randomly (e.g., 'Service Airbag' message)
• Features managed by the BCM may not work (e.g., power locks, windows, interior lights)
• Vehicle may not start (no crank) or may start and immediately stall.
• Radio display is blank or inoperative.
• Steering wheel controls are not illuminated or are inoperative.
• No audible feedback (clicking) from turn signals.
• HVAC controls are inoperative.

Most Likely Causes

1. Poor Connection at Serial Data Gateway Module (SDGM) 🔴 High Probability This is a well-documented issue cited in multiple revisions of GM Technical Service Bulletin #PIT5586. The terminals in the X1 (Gray) and X2 (Black) connectors of the SDGM can lose proper tension, become bent, or back out, causing intermittent data loss.
   How to confirm: Visually inspect the X1 and X2 connectors at the SDGM, which is located under the driver's side of the dashboard, to the left of the steering column. After disconnecting the battery, unplug the connectors and check for any loose-fitting terminals, corrosion, or damage. A gentle tug on each wire can reveal a backed-out terminal.
   Typical fix: Repairing the affected terminals by ensuring they are fully seated and have proper tension. In some cases, the connector pigtail may need to be replaced. The black X2 connector pigtail is available as ACDelco part #PT2713 (GM #13584095).
   Est. part cost: $5-$50
2. Serial Data Gateway Module (SDGM) Logic Lock or Failure 🟡 Medium Probability The SDGM can enter a 'logic lock' state where it stops communicating correctly. This is a known software/hardware glitch on this platform, addressed in TSBs like PIT5586G and 20-NA-212. In some cases, a dealer-installed software update can permanently fix the anomaly.
   How to confirm: First, attempt a hard reset by disconnecting the battery or, more specifically, by pulling the fuse for the SDGM (labeled F26DL in the left-side instrument panel fuse block) for at least 60 seconds. If symptoms disappear temporarily, it points to a logic lock. If the problem persists after confirming good connections, the module itself may have failed.
   Typical fix: In cases of a logic lock, a reset may suffice, but a software update from a GM dealer is the long-term solution. If the module has failed, it must be replaced and will require programming by a dealer or a qualified shop with GM-specific software.
   Est. part cost: $80-$200
3. Faulty Body Control Module (BCM) ⚪ Low Probability
   How to confirm: This should only be considered after ruling out all SDGM and wiring issues, as it is a common misdiagnosis. Diagnosis requires a bi-directional scan tool to test BCM functionality and monitor its data output directly after confirming the SDGM and network are healthy.
   Typical fix: Replacement of the BCM, which requires programming to the vehicle's VIN and options.
   Est. part cost: $250-$450
4. Wiring Harness Issue ⚪ Low Probability A poor ground connection at G218, located behind the driver's side kick panel near the A-pillar, is a known cause for BCM-related communication issues on this platform.
   How to confirm: Perform a continuity and resistance check on the CAN bus wiring between the BCM, SDGM, and the module that set the code (e.g., ECM). Check for shorts to power or ground. Specifically inspect and clean the G218 ground connection.
   Typical fix: Repair the damaged section of the wiring harness or clean/tighten the G218 ground connection.
   Est. part cost: $10-$100

Rare But Worth Checking

• Low Battery Voltage or Charging System Fault: Unstable voltage can cause communication errors between modules. Before diving into complex network diagnostics, always ensure the battery and alternator are functioning correctly. Resting voltage should be above 12.4V, and running voltage should be between 13.7-14.7V.

Diagnosis Steps

1. Scan for all DTCs in all modules. Note if other 'U' codes are present, which points towards a network fault.
2. Check and verify battery voltage is stable and within spec (~12.4V+ engine off, ~13.7-14.7V engine on).
3. Perform a targeted reset by pulling the SDGM fuse (F26DL in the driver-side dash fuse panel) for at least 60 seconds to see if the fault is a temporary 'logic lock'. Reinstall and check if symptoms have cleared.
4. If the code returns, disconnect the negative battery terminal. Locate the SDGM under the driver's side dashboard, to the left of the steering column.
5. Following the guidance of TSB #PIT5586, carefully disconnect the gray X1 and black X2 connectors from the SDGM and inspect the terminals for looseness, corrosion, backed-out pins, or damage. A gentle tug on each wire can reveal a loose terminal.
6. If terminals are loose or damaged, they must be repaired. The connector pigtail may need to be replaced (e.g., ACDelco PT2713 for the black X2 connector).
7. If connectors are good, inspect the main BCM ground point G218, located behind the driver's side kick panel, for tightness and corrosion.
8. If connections and grounds are good, the next step is to use an advanced scan tool to monitor the CAN bus network status. If the SDGM is not communicating or is causing errors, it is the likely point of failure.
9. Only after confirming the SDGM and its wiring/grounds are good should the Body Control Module (BCM) be considered the cause.

Parts You'll Likely Need

• Serial Data Gateway Module (OEM #84351137) — This module is the most common point of failure for this code on this platform, either due to internal faults or logic lock. Part number may vary; always verify with VIN.
  Trusted brands: ACDelco (Genuine GM)
  OEM price range: $120-$200
  Aftermarket price range: $80-$150
• Connector Pigtail (SDGM X2) (OEM #13584095 (ACDelco PT2713)) — As per TSB #PIT5586, loose or damaged terminals at the SDGM's black X2 connector are a primary cause. Replacing the pigtail is a common repair.
  Trusted brands: ACDelco
  OEM price range: $25-$40
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• U0020, U0029, U0073, U0100, U0101, U0140, etc. — The provided TSB #PIT5586B and its successors list U0422 with numerous other 'U' (network) codes. The presence of multiple communication codes strongly suggests a central network problem, such as the SDGM, rather than a single failed module.

Technical Service Bulletins (TSBs) & Recalls

• PIT5586B: Addresses multiple communication DTCs, including U0422, and points to checking the Serial Data Gateway Module X2 connector for terminal issues.
• PIT5586E / PIT5586G / 20-NA-212: Later revisions of the same bulletin that add information about SDGM 'logic lock' and recommend a fuse pull reset or software update as potential fixes.

Platform-Specific Known Issues

• TSB #PIT5586B and its later revisions (E, G) explicitly list U0422 as a potential code resulting from terminal concerns in the Serial Data Gateway Module's X1 and X2 connectors. It instructs dealers to check and repair these connections as needed.
• Later TSBs (PIT5586G, 20-NA-212) also address a 'logic lock' condition that can be temporarily fixed by pulling fuse F26DL for 60 seconds and may be permanently resolved with a dealer-installed software update.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: ~60 Ohms. Failure: A reading of ~120 Ohms indicates an open circuit or a missing terminating resistor (e.g., a module is unplugged). A reading significantly less than 60 Ohms suggests a short between the CAN lines.
• CAN Bus Voltage (Dominant State) — expected: CAN High (Pin 6): ~3.5V, CAN Low (Pin 14): ~1.5V. Failure: Voltages that are stuck high, low, or at the same potential indicate a bus fault or failed module.
• CAN Bus Voltage (Recessive/Idle State) — expected: CAN High (Pin 6) and CAN Low (Pin 14) should both be at ~2.5V.. Failure: Deviation from 2.5V on either line when the bus is idle points to a fault.
• BCM Power Supply Ripple — expected: Less than 0.5V ripple on the 12V supply.. Failure: Voltage ripple greater than 0.5V can scramble the module's output and cause communication errors.

Hidden / Shadow Codes Worth Checking

• U0422-71: Invalid Data Received From Body Control Module - Actuator Stuck. This is a GM-specific symptom byte that provides more detail than the base code. It suggests the invalid data is related to a body actuator (e.g., door lock, window motor, HVAC blend door) that the BCM controls. (see via A professional-grade scan tool like the GM GDS2 will display the two-digit symptom byte after the main DTC.)

Scan Tool Commands That Help

• GDS2 (GM Global Diagnostic System 2): BCM Control Functions (e.g., 'Headlamp Relay', 'Passenger Window Motor') — After confirming the network is physically intact (60 Ohm resistance), use these bidirectional controls to command BCM outputs directly. If the headlights, windows, locks, etc., operate correctly when commanded by the scan tool, it proves the BCM and its output circuits are functional, strongly suggesting the fault is in the communication path (SDGM, wiring) rather than the BCM itself.
• GDS2 / SPS (Service Programming System): SDGM Programming/Setup — This is required after replacing the Serial Data Gateway Module. The new module must be programmed to the vehicle's VIN and configuration.
• GDS2: Vehicle-Wide Programming (VWP) Recovery — If a programming event fails across multiple modules, a known issue with the SDGM may be the cause. A GM document suggests pulling the SDGM fuse for 2 minutes to reset a logic lock, then re-attempting programming. This confirms the 'fuse pull' is a dealer-acknowledged procedure.

Wiring & Ground Locations

• G218 — Behind the driver's side kick panel, near the A-pillar and the driver's side dash speaker.. This is a primary ground point for the BCM. A TSB and numerous owner reports confirm that sound-deadening insulation material can get trapped between the ground ring terminal and the body stud, creating a high-resistance connection. This poor ground can cause the BCM to malfunction and send invalid data, triggering U0422, especially when electrical load increases (like turning the steering wheel).
• Engine Harness Chafe Points — Common chafe points for the main engine harness on the K2XX platform include the front corner of the left cylinder head, the ECM/TCM bracket, the left front upper control arm, and the shock tower bolt.. While not specific to the BCM, the CAN bus wiring runs through these harnesses. A chafe that shorts a CAN wire to ground or another wire will corrupt the entire network, leading to multiple 'U' codes, including U0422. These locations should be inspected if direct SDGM/BCM checks do not resolve the issue.
• Negative Battery Cable Chafe Point — Where the main negative battery cable passes the exhaust manifold on the passenger side.. A forum user reported that the insulation on their negative battery cable melted in this location, causing the wire to corrode. A compromised main battery ground can lead to unstable voltage and widespread, intermittent electrical faults that mimic module failures.

Real Owner Repair Stories

• YouTube user testimony (2014-2018 Chevrolet Silverado) — Headlights and dash lights flickering/dimming when using brakes or turn signals. Later escalated to the truck completely shutting off, loss of electric power steering, and multiple dash warnings like 'park assist disabled'.
  ❌ Tried (didn't work) Testing the battery and alternator, both of which checked out as fine.
  ✅ What actually fixed it The G218 ground was faulty. Sound deadening material was trapped under the ground nut, causing a poor connection. Cleaning the connection and ensuring the insulation was clear of the stud resolved all electrical issues.
• Reddit user in r/Silverado (2014-2018 Chevrolet Silverado) — Intermittent 'Service Stabilitrak' message on the dash.
  ✅ What actually fixed it The user was advised by others that the cause was the G218 ground. The fix involved accessing the ground behind the driver's side kick panel and ensuring it had a clean, tight connection.

"I Checked Everything" — The Actual Cause

• A common scenario for this code is that all standard network tests (like a CAN bus resistance check) will pass, and no visible wiring damage will be found. The root cause is often a high-resistance connection at the G218 ground point behind the driver's kick panel. This poor ground may only cause a problem under high electrical load (e.g., turning the power steering at low speeds), causing the BCM to send corrupt data intermittently. A technician simply checking for continuity at G218 might see a good connection, but a voltage drop test under load is required to expose the fault.