B1038 on 2021-2022 Cadillac Escalade: Door Ajar Message Causes and Fixes

What's Unique About the 2021-2022 Cadillac ESCALADE

Unlike many vehicles where a door ajar issue points to a bad latch or switch, on these specific GM T1XX platform SUVs, the problem is a known software or internal BCM fault. General Motors issued a Technical Service Bulletin (TSB 22-NA-052) explicitly warning technicians NOT to replace the door latch assembly as a first step. This is a critical distinction, as forum discussions for older GM SUVs frequently (and correctly for those models) point to faulty door lock actuators or switches, a repair path that would be incorrect for this specific problem. The issue is so common that GM has prescribed a specific BCM reset procedure as an interim fix while a permanent software update is developed.

Diagnostic Flowchart

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

Symptoms You May Notice

• A 'Door Ajar' message stays on the Driver Information Center (DIC) when all doors are closed.
• Interior dome lights may not turn off, leading to potential battery drain.
• Vehicle alarm may not arm or may sound unexpectedly.
• Inability to lock the doors using the remote or interior buttons.
• Customer may report that door latches are inoperable.

Most Likely Causes

1. Body Control Module (BCM) Internal Fault 🔴 High Probability → Shop Body Control Module This is a documented issue acknowledged by General Motors in TSB #22-NA-052, which points to an 'internal fault within the body control module (BCM)', likely software-related. GM has revised the bulletin multiple times, expanding its scope and indicating an ongoing investigation into a permanent software fix as of late 2022.
   How to confirm: Confirm the presence of DTC B1038 with symptom byte 64 using a professional scan tool. If the code is present and a door ajar message is displayed with no actual door being open, the BCM is the confirmed cause per the TSB.
   Typical fix: The official interim fix is to reset the BCM 🎬 Watch a quick guide on how to reset the BCM. by removing fuses F49DR and F4DR for five minutes. The permanent fix is a BCM software update performed by a GM dealership. This reset procedure is covered under warranty with labor operation code 2888588.
   Est. part cost: $0

Rare But Worth Checking

• Faulty Door Latch Assembly: → Shop Door Latch Assembly While TSB #22-NA-052 explicitly warns against replacing the latch first, a genuine failure of the ajar switch within the latch is still possible. This should only be considered if the BCM reset and subsequent dealer software update fail to resolve the issue, as instructed by the TSB's note to 'follow normal SI diagnostics' if the DTC returns.
• Wiring Harness Damage: Damage to the wiring between the door and the vehicle body (especially in the flexible rubber boot) can cause an open or short in the ajar switch circuit. This is a standard diagnostic step but should only be pursued after the BCM-specific procedures from the TSB have been completed without success.

Diagnosis Steps

1. Verify the customer complaint: Check for a 'Door Ajar' message on the DIC or inoperable latches.
2. Scan the Body Control Module (BCM) for codes. Confirm that DTC B1038 with symptom 64 is present.
3. Follow GM TSB #22-NA-052: Power off the vehicle.
4. Locate the interior fuse block and remove the fuses 🎬 See how to access the fuse box and remove the cover. for VBATT01 (F49DR BCM1) and VBATT02 (F4DR BCM 2).
5. Wait for a full 5 minutes before reinstalling the fuses.
6. Clear all DTCs with a scan tool and verify that B1038 has not returned.
7. If the code returns immediately or soon after, the vehicle requires the BCM software update from a GM dealer. This procedure is designated as Labor Operation 2888588 and takes approximately 0.3 hours under warranty.
8. If the code still persists after a software update, the TSB advises to 'follow normal SI diagnostics,' which would include checking the door latch switch and wiring for the affected door.

Parts You'll Likely Need

• No parts typically required — The official fix is a BCM reset or a software update, not a part replacement.
  OEM price range: $0
  Aftermarket price range: $0
• Body Control Module (BCM) (OEM #13548775, 13547768, 13541808) — For reference only. This part should NOT be replaced for this code unless all TSB procedures fail and the module is diagnosed as having a complete internal hardware failure.
  Trusted brands: ACDelco (OEM)
  OEM price range: $90 - $190
  Aftermarket price range: $80 - $150

Related Codes That Often Appear With This One

• B2A00: The November 2022 revision of TSB 22-NA-052 added 'B2A00' to its list of additional SI keywords related to this issue.

Technical Service Bulletins (TSBs) & Recalls

• 22-NA-052 (revised Nov 21, 2022): 'Diagnostic Trouble Code (DTC) B1038 SYM64 Set in Body Control Module (BCM) and Door Ajar Message on Driver Information Center (DIC)'. This bulletin is the primary source, identifying the cause as an internal BCM fault and providing the fuse-pull reset procedure. The latest revision expanded the affected regions and added B2A00 as a related keyword.

Platform-Specific Known Issues

• A known condition on 2021-2022 GM SUVs, including the Cadillac Escalade, where the BCM can falsely set a B1038 code, causing a door ajar warning. This is documented in TSB #22-NA-052.
• The BCMs used in these 2021+ GM SUVs were placed on part restriction by GM for a period, requiring dealers to contact a special engineering group (PQC) before ordering a replacement. This indicates a known sensitivity and high-level monitoring of BCM issues on this platform.

Hidden / Shadow Codes Worth Checking

• B1038 SYM64: Indicates a 'Signal Plausibility Failure' for the door ajar circuit. This means the BCM received a signal that was illogical, which is more indicative of a software or internal module fault than a simple broken wire or switch. (see via GM GDS2 or other professional scan tools capable of reading manufacturer-specific symptom codes.)

Scan Tool Commands That Help

• GDS2 (GM Dealer Tool): Network Communication Status — To verify which modules are communicating on the various CAN bus networks. This is a crucial first step if multiple 'U' (communication) codes are present alongside B1038, as it can help isolate a broader network problem from a single module fault.
• GDS2 (GM Dealer Tool): SPS (Service Programming System) — This is used to perform the BCM software update that is the permanent fix for the B1038 code. It is also used for a larger 'VeSCoM' (Vehicle Software Configuration Management) update that bundles fixes for multiple modules, including one for 'Service Theft Deterrent System' messages from the BCM.
• GDS2 (GM Dealer Tool): Clear All DTCs — This function is required after performing the fuse-pull reset procedure as specified in TSB 22-NA-052 to confirm the code does not immediately return.

Wiring & Ground Locations

• G218 — Under the driver's side dash, sometimes behind the speaker grille or kick panel.. While not directly cited for B1038, G218 is a known problematic ground point for the BCM on this platform that causes a host of other electrical issues and communication codes (like U0140). A poor ground here can cause erratic BCM behavior, and checking that it is clean and tight is a wise preliminary step for any BCM-related code.
• Door Latch Connector — Inside each door, plugging directly into the latch assembly.. If the BCM software update fails to fix the issue, 'normal SI diagnostics' would require testing the door ajar switch circuit. This involves unplugging the connector at the latch to see if the 'ajar' signal disappears, which would isolate the fault to the latch assembly itself.

Real Owner Repair Stories

• Tahoe Yukon Forum (2021 GMC Yukon Denali) — Vehicle was completely dead after an Over-the-Air (OTA) update alert appeared the previous day. Required a trickle charge and jump start.
  ❌ Tried (didn't work) Initial jump start.
  ✅ What actually fixed it The dealer determined the battery was failing and would only hold a partial charge. They replaced the battery, forced the software update to complete, and cleared all codes. The user speculated that the low battery voltage caused the OTA update to fail, leaving modules in a bad state.

OEM Part Supersession History

• 13536380, 13541808, 13546978 → 13548775 — Standard part evolution and potential internal revisions to address known issues.
  Heads up: While older numbers are superseded, using the latest part number (13548775) is critical to ensure it has the latest hardware revisions before programming.