P0513 on 2015-2017 Chevrolet Silverado: Causes and Fixes for Incorrect Immobilizer Key

What's Unique About the 2015-2017 Chevrolet SILVERADO

While any vehicle can have a key or immobilizer failure, the 2015-2017 Silverado (and its K2XX platform mates like the Sierra, Tahoe, and Suburban) is uniquely prone to setting a P0513 code due to known electrical vulnerabilities. GM has issued Technical Service Bulletins (TSBs) acknowledging that wiring routed under the driver's door sill is susceptible to moisture and corrosion, and that a specific BCM ground point (G218) under the dash can be faulty from the factory. These electrical faults, specifically an open in Circuit 5199, can prevent the KR73 Ignition Run Relay from activating, causing a no-start condition that logs a P0513 code and leads many to mistakenly replace keys or modules when the real problem is a simple wiring or ground repair.

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 start or 'cranks but won't fire'.
• Engine starts and immediately stalls.
• Check Engine Light is on.
• Security light on the instrument panel is on or flashing.
• "Service 4WD" message may appear on the dash, often related to the same wiring harness issue.
🎬 Watch this guide on GM truck electrical ground maintenance.
• Instrument Panel Cluster goes blank or is inoperative.
🎬 Watch this diagnostic walkthrough for a Silverado with no dash lights.
• Radio or center stack display goes blank.

Most Likely Causes

1. Damaged or Corroded Wiring in Driver's Sill Plate 🔴 High Probability The main body harness is routed in a channel under the driver's side door sill, an area prone to water, salt, and physical damage. TSB #PIT5391E and its revisions specifically identify this as a cause for P0513.
   How to confirm: Remove the plastic driver's side door sill plate(s) and peel back the carpet to expose the wiring harness. Carefully unwrap the harness tape and inspect for signs of corrosion (green or white powder), chafing, or broken wires. Pay close attention to factory splice points and Circuit 5199 (often a Green/Violet, Tan/Yellow, or Purple wire).
   Typical fix: Repair the damaged section of wire, often Circuit 5199, using waterproof butt connectors and heat shrink tubing. This circuit provides the control signal for the KR73 Ignition Run/Crank Relay. Solder and heat shrink provide a more robust repair.
   Est. part cost: $10-$50
2. Poor Body Control Module (BCM) Ground (G218) 🟡 Medium Probability TSB #PIT5405C notes that dash insulator material can get trapped between the ground eyelet and the chassis during assembly, causing a poor connection for the BCM.
   How to confirm: Locate ground G218 under the driver's side of the dashboard, on the metal support structure behind the A-pillar trim, near the driver's side speaker. Disconnect the 10mm nut and check for trapped insulation material. The connection should be clean, bare metal to metal.
   Typical fix: Remove the ground nut, cut away any trapped insulation material, clean the contact surfaces of the eyelet and the chassis with a wire brush, and securely re-tighten the ground. 🎬 See how to locate and fix the G218 ground point.
   Est. part cost: $0-$5
3. Weak or Dead Key Fob Battery ⚪ Low Probability
   How to confirm: Try starting the vehicle with a spare key. If the spare key works reliably, the battery in the primary key fob is the most likely cause.
   Typical fix: Replace the CR2032 battery inside the key fob.
   Est. part cost: $1-$10
4. Faulty Immobilizer Key ⚪ Low Probability
   How to confirm: If a new battery doesn't fix the key and the spare key works, the transponder chip in the primary key may have failed. This is a diagnosis of exclusion after checking wiring and grounds.
   Typical fix: Replace the faulty key and have the new key programmed to the vehicle by a dealership or qualified automotive locksmith.
   Est. part cost: $75-$250

Rare But Worth Checking

• BCM Reprogramming Needed After Low Voltage Event: TSB #21-NA-277 describes a specific scenario where P0513 can set after a battery event (jump start, replacement, etc.) and the vehicle won't start. The official fix is not to replace parts, but for a dealer to perform a special BCM reset/reprogram procedure.
• Low Vehicle Battery Voltage: Modern vehicle electronics are sensitive to low voltage. A weak main vehicle battery can cause communication errors between modules, triggering a false P0513 code.
• Faulty Body Control Module (BCM): This is rare and should only be considered after all wiring, ground, and key-related issues have been definitively ruled out. Replacement requires professional programming.

Diagnosis Steps

1. Scan for all stored trouble codes. Note any communication (U-codes) that accompany P0513, as they strongly suggest a wiring or ground fault.
2. Try starting the truck with a known-good spare key. If it starts, the problem is likely with your primary key or its battery.
3. If the spare key does not work, test the main vehicle battery. It should read ~12.6 volts at rest. A voltage below 12.2V can cause random electrical issues.
4. Remove the driver's side door sill trim plates and peel back the carpet to expose the large wiring harness in the floor channel.
5. Carefully unwrap the harness and inspect for any signs of water damage, corrosion (especially green/white powder on wires), or physical damage. Pay close attention to factory splice points and the wire for Circuit 5199.
6. Locate and inspect the BCM ground G218. It is on the metal support structure under the dash, behind the driver's side A-pillar trim. Remove the 10mm nut and ensure it is clean, tight, and free of any trapped insulation material.
7. If sill plate wiring appears intact, inspect fuse block connectors. Per TSB PIT5391D, check 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), both related to Circuit 5199.
8. If all wiring and grounds are confirmed to be good, the issue may lie with the key transponder or a BCM that needs reprogramming per TSB 21-NA-277, which may require professional diagnosis.

Parts You'll Likely Need

• Waterproof Butt Connectors / Wiring Repair Supplies — Used to repair the commonly corroded wires (Circuit 5199) found under the driver's side sill plate, which is the most frequent cause of P0513 on this truck.
  Trusted brands: 3M, Ancor
  Aftermarket price range: $10-$25
• Key Fob Battery (OEM #CR2032) — The simplest and cheapest potential fix if the issue is isolated to a single key.
  Trusted brands: Energizer, Duracell
  OEM price range: $5-$10
  Aftermarket price range: $1-$5
• Transponder Key / Key Fob (OEM #23209427, 22984996, 13594763) — Replaced only after confirming the key itself is faulty and all wiring/ground issues have been ruled out. Requires professional programming.
  Trusted brands: ACDelco, Strattec
  OEM price range: $75-$150
  Aftermarket price range: $40-$90

Related Codes That Often Appear With This One

• U0073 — This and other U-codes (U0140, U0126, U0121, U0101, U0100) often appear with P0513 when the root cause is the poor BCM ground at G218, as cited in TSB #PIT5405C.
• P262B — This code is mentioned alongside P0513 in TSB #PIT5391E, as it can also be triggered by the wiring issues under the driver's sill plate that affect ignition relay control.
• B1325 — Relates to Device Power Circuit Voltage and is mentioned in TSBs as another code that can appear with P0513 due to the sill plate wiring harness corrosion.

Technical Service Bulletins (TSBs) & Recalls

• PIT5391E: Addresses P0513 caused by damaged/corroded wiring (Circuit 5199) in the driver sill plate area.
• PIT5405C: Links P0513 and many other codes to a poor BCM ground at the G218 location due to a trapped insulator mat.
• 21-NA-277: Details a scenario where P0513 sets after a low-voltage event, requiring a BCM reprogram instead of parts replacement.

Platform-Specific Known Issues

• Sill Plate Wiring Corrosion (TSB PIT5391E): TSB #PIT5391E and its successors directly link P0513 to damaged or corroded wiring in the driver's sill plate area. The bulletin explains this is often due to an open or high resistance in Circuit 5199, which prevents the KR73 Ignition Run Relay from activating, causing a no-start condition.
• BCM Ground G218 Fault (TSB PIT5405C): TSB #PIT5405C identifies a faulty Body Control Module ground at location G218 as a cause for P0513 and a host of other communication codes. The problem is specifically caused by the dash insulator mat being trapped under the ground lug during factory assembly, creating a high-resistance connection.

Mechanic-Grade Diagnostic Values

• Voltage Drop on BCM Ground G218 — expected: Less than 0.1 Volts. Failure: A reading greater than 0.3V indicates an unacceptable high-resistance connection that must be repaired.
• Ignition 1 Voltage on Circuit 5199 — expected: Should be equal to battery voltage (~12.6V with key on, engine off; ~14V+ with engine running).. Failure: Voltage that is low or 0V indicates an open or high resistance in the circuit, likely in the driver's sill plate harness, or that the KR73 relay is not activating.
• G218 Ground Nut Torque — expected: 7 Nm (62 lb-in). Failure: A loose nut can cause an intermittent connection, 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 (e.g., battery replacement, jump start). (see via A dealer-level scan tool like GM GDS2 is required. This code is a key indicator for the condition described in TSB #21-NA-277.)
• B3978, B3979, B3980, B3981: These are 'Environment ID' DTCs. If three or more are present and current in the BCM along with P0513, it is a primary indicator for the software corruption condition that requires a BCM recovery procedure, not parts replacement. (see via Visible with a GM GDS2 scan tool. Their presence confirms the scenario outlined in TSB #21-NA-277.)

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 the BCM. This may require a special VCI from GM TAC.
• GM GDS2 (Global Diagnostic System 2): Immobilizer Learn — This function is used to program new keys to the vehicle. It is only used *after* a key or BCM has been replaced and all underlying wiring/ground/software issues have been resolved.
• GM GDS2 (Global Diagnostic System 2): View DTC and ID Information — Required to view the hidden 'B' codes (like B389A) and 'Environment ID' codes that are critical for diagnosing the TSB #21-NA-277 software issue.

Wiring & Ground Locations

• Circuit 5199 — A Green/Violet (GN/VT) wire originating at the BCM connector X4, pin 15. It runs through the main harness under the driver's side door sill plate to the KR73 Ignition Main Relays.. This circuit provides the control signal for the ignition relays. Corrosion or an open in this wire, common in the sill plate area, prevents the relays from activating, causing a no-start and logging P0513.
• G218 — A primary ground point located under the driver's side dashboard, on the metal support structure behind the A-pillar trim, near the driver's side speaker.. This is the main ground for the Body Control Module (BCM). A poor connection here, often due to trapped insulation from the factory, can cause P0513 and a flood of other communication (U-series) codes.
• X50A — The underhood fuse block, located on the driver's side of the engine compartment.. Houses one of the two KR73 Ignition Main Relays. TSBs direct technicians to check connector X4, pin M5 for issues related to Circuit 5199.
• X51L — The left instrument panel fuse block, located on the driver's side of the dashboard, behind a trim cover.. Houses the second KR73 Ignition Main Relay. TSBs direct technicians to check connector X1, pin 42 for issues related to Circuit 5199.

Real Owner Repair Stories

• Synthesized from multiple forum discussions and technician reports (2016 Chevrolet Silverado 1500) — Intermittent no-start, cranks but won't fire. Security light is on, and code P0513 is stored, sometimes with a 'Service 4WD' message.
  ❌ Tried (didn't work) Replacing the battery in the key fob., Trying the spare key., Replacing the vehicle battery., Initial shop diagnosis suggested replacing the BCM or buying a new key, which was declined.
  ✅ What actually fixed it Owner removed the driver's side sill plate and peeled back the carpet. After unwrapping the harness, a corroded factory splice containing a Green/Violet wire (Circuit 5199) was discovered. The corroded section was cut out, and a new piece of wire was spliced in using waterproof heat-shrink butt connectors. The code was cleared and did not return, resolving the no-start issue.