P0513 on 2015-2017 GMC Sierra: Causes and Fixes for Incorrect Immobilizer Key

What's Unique About the 2015-2017 Gmc SIERRA

While P0513 universally points to an immobilizer key issue, on the 2015-2017 K2XX generation of GMC Sierra, the root cause is frequently not the key itself. GM has issued specific Technical Service Bulletins (TSBs) that identify common electrical faults as the trigger. These trucks are known to develop corroded wiring in the driver's sill plate area, specifically an open or high resistance in Circuit 5199 which powers an ignition relay. They are also known for grounding issues at the Body Control Module ground G218, where a dash insulator mat gets trapped under the ground terminal, creating a poor connection that can mimic a key failure and set this code.

Diagnostic Flowchart

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

Symptoms You May Notice

• Engine will not crank or start
• Engine starts and immediately stalls
• Flashing security light on the instrument panel
• Check Engine Light is on (though TSB #PIT5391E notes it may not always illuminate for this fault).
• Message on the dash indicating a key or theft system problem (e.g., 'Service Theft Deterrent System 🎬 Watch: How to reset the theft deterrent system on your Sierra.')
• Multiple other warning lights may appear, such as 'Service Stabilitrak' or 'Service 4WD', due to the underlying electrical fault.

Most Likely Causes

1. Damaged or Corroded Wiring in Driver's Sill Plate 🔴 High Probability Water intrusion and wear can damage wiring harnesses that run along the driver's side floor. GM TSB #PIT5391F specifically calls out an open or high resistance in Circuit 5199 (Ignition 1 voltage) in this location as a cause for a no-start and code P0513.
   How to confirm: Remove the driver's side front and rear sill plates and peel back the carpet to physically inspect the large wiring harness in the trough. Carefully unwrap the harness tape and look for signs of green or white corrosion, chafing, or broken wires, particularly around factory splice points. 🎬 See this walkthrough on finding and fixing common GM ground issues.
   Typical fix: Repairing the affected wire(s) by cutting out the corroded section and splicing in a new piece of wire using waterproof heat-shrink butt connectors. Ensure the repaired area is well-taped and protected from future moisture.
   Est. part cost: $5-$25 for wiring repair supplies.
2. Poor Body Control Module (BCM) Ground (G218) 🔴 High Probability GM TSB #PIT5405C notes that the dash insulator mat can get trapped between the ground eyelet and the chassis at location G218, creating a poor connection. This ground is critical for the BCM and many other modules, and a bad connection causes a host of electrical issues, including P0513.
   How to confirm: Locate ground G218, which is on the driver's side A-pillar, behind the dash trim panel near the speaker. Visually inspect it to see if the black sound-deadening mat is pinched under the ground terminal. The connection should be clean and tight.
   Typical fix: Remove the ground nut, pull the ground terminal away, and trim the insulation mat so it cannot interfere with the connection. Clean the eyelet and the chassis surface with a wire brush or sandpaper, re-secure the connection, and torque the nut to 7 Nm (62 lb-in).
   Est. part cost: $0-$5 for cleaning supplies.
3. Faulty or Unprogrammed Key 🟡 Medium Probability
   How to confirm: Try starting the vehicle with a spare, known-good key. If the spare key works, the original key is likely faulty. If neither key works, the problem is almost certainly with the vehicle's wiring or grounds, not the keys.
   Typical fix: Replacing the faulty key and having the new one programmed to the vehicle by a dealer or qualified automotive locksmith. OEM part numbers vary but include 23209427, 22984996, and 23286589.
   Est. part cost: $75-$250 for a new key and programming.
4. Low Vehicle Battery Voltage ⚪ Low Probability Modern trucks are sensitive to low voltage. TSB #21-NA-277 notes that P0513 can appear after a low voltage condition, jump start, or battery replacement, which can corrupt module communication without there being a permanent hardware fault.
   How to confirm: Test the battery with a multimeter or a battery tester. A reading below 12.4 volts with the engine off suggests a weak battery. The code may have appeared immediately following a battery event.
   Typical fix: Charging or replacing the vehicle's 12V battery. In some cases, a BCM 'restore' procedure may be needed by a dealer to clear the code if it persists after the voltage is stabilized, as per TSB #21-NA-277.
   Est. part cost: $150-$300 for a new battery.

Rare But Worth Checking

• Faulty Body Control Module (BCM): If all wiring, grounds, and keys have been ruled out, the BCM itself could be the issue. This is an expensive last resort and requires professional diagnosis.
• Aftermarket Remote Starter or Alarm: Improperly installed aftermarket systems can interfere with the factory Pass-Key III+ immobilizer system, causing intermittent P0513 codes and no-start conditions.
• Improperly Hardened Ground Bolts: TSB #PIT5562 indicates a small population of 2017 models built at the Ft. Wayne Assembly plant may have ground bolts that were not properly hardened, preventing a secure connection and causing various electrical faults. This could affect multiple ground locations, not just G218.

Diagnosis Steps

1. Scan for all diagnostic trouble codes. Pay close attention to any communication (U-codes) or other BCM-related codes, as they often point to a ground issue.
2. Try starting the vehicle with all known spare keys to rule out a single faulty key.
3. Test the state of charge and health of the vehicle's 12-volt battery. Note if the issue began after a jump start or battery change.
4. Following TSB #PIT5405C, inspect the BCM ground at location G218 (driver's side A-pillar, behind dash trim). Ensure it is clean, tight, free of trapped insulation, and torqued to 7 Nm (62 lb-in).
🎬 Watch: How to fix the G218 ground connection step-by-step.
5. Following TSB #PIT5391F, pull the driver's side sill plate and inspect the wiring harness, specifically looking for corrosion or damage to Circuit 5199.
6. Repair any damaged wiring found in the sill plate area using waterproof connectors.
7. If the issue started after a low-voltage event and no physical faults are found, consult a dealer about the BCM restore procedure mentioned in TSB #21-NA-277.
8. If no issues are found, further diagnosis of the immobilizer antenna, BCM, and key transponder system with a professional scan tool may be needed.

Parts You'll Likely Need

• Wiring Repair Supplies — The most common cause, according to TSBs, is damaged wiring that needs to be repaired, not replaced.
  Trusted brands: 3M, Dorman
  Aftermarket price range: $5-$25
• Transponder Key (Circle Plus) (OEM #23209427, 22984996, 23286589, 23286588, 23326748) — If the key itself has failed, it will need to be replaced and programmed. This should only be done after verifying the common wiring/ground issues are not present.
  Trusted brands: ACDelco
  OEM price range: $100-$200
  Aftermarket price range: $50-$100

Related Codes That Often Appear With This One

• P262B — TSB #PIT5391E explicitly links P0513 and P262B to the same wiring issue (Circuit 5199) in the driver's sill plate.
• U0073, U0140, C0544, etc. — TSB #PIT5405C lists a large number of communication codes that can appear with P0513, all pointing to the common cause of a bad BCM ground at G218. Seeing a flood of U-codes strongly suggests a ground or power supply issue.

Technical Service Bulletins (TSBs) & Recalls

• PIT5391E: Addresses P0513 caused by damaged/corroded wiring (Circuit 5199) in the driver sill plate.
• PIT5405C: Addresses P0513 and other codes caused by a poor BCM ground at location G218.
• 21-NA-277: Notes that P0513 can be set after a low voltage event and may require a BCM software restore.
• PIT5562: Warns of improperly hardened ground bolts on a small batch of 2017 models from the Ft. Wayne plant

Platform-Specific Known Issues

• TSB #PIT5391F documents that P0513 can be caused by damaged or corroded wiring in the driver's sill plate area, specifically affecting Circuit 5199.
• TSB #PIT5405C identifies a poor ground connection at G218 (for the Body Control Module) as a cause for P0513 and numerous other communication codes. This is often due to an insulator mat being trapped under the ground terminal.
• Owner experiences shared in online forums and videos confirm that these two TSB-related fixes are the most common solutions, often after a dealer initially misdiagnosed the problem as a bad key or BCM.

Mechanic-Grade Diagnostic Values

• Battery Voltage (Engine Off) — expected: Approximately 12.6 Volts. Failure: A reading below 12.4V indicates a weak battery that can cause module communication errors and set P0513.
• Battery Voltage (Engine Running) — expected: Above 13.7 Volts. Failure: Voltage below 13.7V indicates a charging system issue that can lead to low voltage conditions and trigger P0513.
• Ground G218 Nut Torque — expected: 7 Nm (62 lb-in). Failure: A loose nut can cause intermittent high resistance, leading to a host of electrical issues including P0513.

Hidden / Shadow Codes Worth Checking

• B389A 00: This BCM code, when present with P0513, strongly indicates a software corruption issue, often triggered by a low-voltage event, as described in TSB #21-NA-277. (see via A dealer-level scan tool like GM GDS2 is required. The TSB notes that if the code is not present, a 30-second battery disconnect/reconnect may be needed to see if it sets.)
• B3978 00, B3979 00, B3980 00, B3981 00: These are Environment ID DTCs. If three or more are present and current in the BCM, it is a key indicator for the software condition described in TSBs related to #21-NA-277. (see via A dealer-level scan tool like GM GDS2 that can read current and history body codes.)

Scan Tool Commands That Help

• GM SPS2 (Service Programming System): BCM Recovery / Programming — This is a specific software procedure used to restore corrupted BCM memory when P0513 is set after a low-voltage event, as per TSB #21-NA-277. It should be performed before replacing any modules.
• GM GDS2 / SPS2: Immobilizer Learn — This function is used to program new keys to the vehicle after replacing a key or the BCM. TSBs warn not to perform this until after a BCM recovery has been attempted if a software glitch is suspected.

Wiring & Ground Locations

• G218 — Located on the driver's side A-pillar, behind the dash trim panel and speaker. It is a ground stud with a 10mm nut.. This is the primary ground for the Body Control Module (BCM). TSB #PIT5405C identifies a poor connection here, often due to trapped insulation, as a direct cause of P0513 and many other communication codes.
• Circuit 5199 (Ignition 1 Voltage) — This wire runs in the main harness under the driver's side sill plate. TSB #PIT5391F points to terminal M5 at connector X4 of the Underhood Fuse Block (X50A) and terminal 42 at connector X1 of the Left I/P Fuse Block (X51L) as key inspection points.. Corrosion or an open in this circuit prevents the KR73 Ignition Main Relay from functioning correctly, leading to a no-start and setting codes P0513 and P262B.
• Underhood Fuse Block (X50A) — The main fuse block located in the engine compartment.. TSB #PIT5391F recommends inspecting connectors at this fuse block, especially connector X4, pin M5 for Circuit 5199, for backed-out or corroded terminals.

Real Owner Repair Stories

• YouTube user comment on a G218 ground fix video (2014-2018 Chevrolet Silverado/GMC Sierra (K2XX Platform)) — Major headache with ground issues.
  ❌ Tried (didn't work) Hours of searching online for a solution.
  ✅ What actually fixed it Following a video to locate the G218 ground, pulling the insulation mat away from the stud, and tightening the ground nut fixed the truck in 30 minutes.

OEM Part Supersession History

• 13542152, 13546980 → 13547771 — Standard part revision and consolidation.
  Heads up: This BCM requires programming and/or special setup procedures upon installation. It is not a plug-and-play part.