B3055 on 2007-2009 Chevrolet Uplander: No-Start Causes and Fixes

What's Unique About the 2007-2009 Chevrolet UPLANDER

The 2007-2009 Uplander and its U-body platform mates use GM's Pass-Key III (PK3) immobilizer system. This system is sensitive to communication breakdowns between the key and the vehicle. While the components are generally reliable, issues often arise from simple failures like a damaged key transponder or a faulty ignition lock housing containing the reader coil. The resulting no-start condition is often misdiagnosed as a bad starter or battery, but the illuminated security light is the key symptom pointing to the anti-theft system. Unlike some other GM systems, disabling the PK3 system is not a straightforward process and fixing the root cause is the recommended repair path.

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. [⭐ MANUFACTURER TSB #PIC5650M, 1]
• Engine starts and immediately stalls. [⭐ MANUFACTURER TSB #PIC5650M, 1]
• Security light is on or flashing on the dashboard. [⭐ MANUFACTURER TSB #PIC5650M, 6, 10]
• "Service Theft System" or "Starting Disabled" message on the driver information center.

Most Likely Causes

1. Defective or Damaged Ignition Key 🔴 High Probability The transponder chip inside the key head is an electronic component that can fail from being dropped, getting wet, or simply from age. A YouTube video with a 2007 Uplander specifically identified using a non-chip 'knockoff' key as the cause of the 'Starting Disabled' message.
   How to confirm: The easiest test is to try starting the vehicle with a known-good spare key. If the spare key works and the original does not, the original key is faulty. A scan tool can also be used to observe if any of the vehicle's keys will start the vehicle.
   Typical fix: Replace the faulty key. A new key must be cut to match and then programmed to the vehicle using a specific 30-minute relearn procedure or a diagnostic scan tool.
   Est. part cost: $50-$150
2. Faulty Ignition Lock Cylinder / Exciter Coil 🟡 Medium Probability The ignition lock cylinder housing contains the exciter coil (antenna) that reads the key's transponder. This component and its wiring are subject to wear from constant use and heat cycles, leading to failure of the coil or its connections.
   How to confirm: If no keys work, the problem is likely with the reader coil. A technician can use a scan tool to monitor the transponder data stream. If the data is absent with all known-good keys, the lock cylinder assembly is the likely culprit. This part is often sold as an assembly including the housing and the sensor.
   Typical fix: Replace the ignition lock cylinder housing assembly. The specific ACDelco part is D1462G (also GM #15795321). After replacement, a security relearn procedure is required to sync the system with the keys.
   Est. part cost: $100-$250
3. Radio Frequency (RF) Interference ⚪ Low Probability The Pass-Key III system operates at 125 kHz and can be disrupted by other RFID devices on the same keychain, such as other car keys, building access cards, or gas station payment fobs. TSB #PIC5650M specifically mentions this as a possible cause, advising to check for aftermarket sources of RFI before replacing parts. [⭐ MANUFACTURER TSB #PIC5650M, 6]
   How to confirm: Remove all other keys, fobs, and cards from the keychain. Try to start the vehicle with only the single Uplander key. If it starts consistently, interference was the cause.
   Typical fix: Keep other RFID devices separate from the ignition key when starting the vehicle.
   Est. part cost: $0
4. Wiring Harness or Connector Issue ⚪ Low Probability The wires running from the ignition lock cylinder down the steering column can chafe or break over time, or the connector pins at the BCM can become loose or corroded. This is more common on vehicles with tilt steering due to the repeated movement of the harness.
   How to confirm: Visually inspect the wiring harness for damage, particularly where it flexes with the steering column. Use a multimeter to check for continuity and proper voltage at the connector for the exciter coil.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the faulty connector.
   Est. part cost: $10-$100

Rare But Worth Checking

• Faulty Body Control Module (BCM): The BCM is the computer that manages the theft deterrent system. It is a rare failure point but should be considered if all other causes have been ruled out. Replacement is expensive and requires professional programming by a dealer or qualified shop with GM-specific software.
• Low Battery Voltage: While a dead battery won't directly cause B3055, very low system voltage during cranking can sometimes cause communication errors within the security system. Ensure the battery is fully charged and connections are clean and tight before diagnosing other components.

Diagnosis Steps

1. Check for the security light on the dashboard. If it's illuminated or flashing, the issue is with the anti-theft system.
2. Remove all other keys, fobs, and RFID cards from the keychain to eliminate radio frequency interference.
3. Try starting the vehicle with a known-good spare key. If it starts, the primary key is defective.
4. If no keys work, inspect the wiring harness around the steering column and ignition lock cylinder for any visible damage.
5. Attempt the 30-minute security relearn procedure. Turn the key to the 'ON' position (do not crank) and wait approximately 10 minutes until the security light turns off or stops flashing. Turn the key to 'OFF' for 10-15 seconds. Repeat this cycle two more times for a total of three cycles and about 30 minutes. After the third cycle, turn the key off 🎬 Watch: Step-by-step walkthrough of the 30-minute security relearn procedure. and then try to start the vehicle.
6. If the relearn fails, use a professional scan tool capable of reading BCM/TDM data to check if the module is detecting a key transponder.
7. If no transponder is detected with any key, the ignition lock cylinder/exciter coil is the most likely failure. The OEM part is ACDelco D1462G.
8. If all else fails, the Body Control Module (BCM) may be faulty, which requires professional diagnosis and replacement.

Parts You'll Likely Need

• Transponder Ignition Key (OEM #GM B111-PT) — The transponder chip inside the key is a common failure point, causing the vehicle to not recognize it. The key must have the 'PK3' stamp on the blade.
  Trusted brands: ACDelco, Strattec
  OEM price range: $70-$120
  Aftermarket price range: $40-$80
• Ignition Lock Cylinder with Passkey Sensor (OEM #ACDelco D1462G / GM 15795321) — This assembly, often called the Ignition Lock Housing, contains the exciter coil that reads the key. It is a common point of failure due to mechanical and electrical wear.
  Trusted brands: ACDelco, Dorman, Standard Motor Products
  OEM price range: $150-$250
  Aftermarket price range: $80-$170

Related Codes That Often Appear With This One

• B3060 — This code for "Unprogrammed Key Transponder" often appears with B3055, indicating the system sees a key but cannot validate its programming. This can happen if a new, unprogrammed key is used.
• B3935 — This code for "Transponder Authentication Failed" can be set alongside B3055 during a communication fault, often pointing to interference or a weak signal from the key.

Technical Service Bulletins (TSBs) & Recalls

• PIC5650M: Addresses an intermittent no crank, no start, or start stall concern with the security light on, list

Platform-Specific Known Issues

• The provided TSB #PIC5650M confirms that intermittent no-crank, no-start, or start-stall conditions with the security light on are a known issue for this platform, with B3055 being a primary diagnostic code. The TSB advises checking for RFI before part replacement. [⭐ MANUFACTURER TSB #PIC5650M, 6]
• A user on RepairPal with a 2006 Uplander reported an intermittent "service anti theft system" message along with data link codes (U1300, U1301), suggesting that wiring issues can manifest as this problem.

Hidden / Shadow Codes Worth Checking

• B3055 00: No Sub Type Information. This symptom byte indicates the base DTC provides the complete description of the failure, and no further detail is available from the sub-code. It confirms the BCM is unable to measure the ignition key transponder value. (see via Dealer-level scan tools like a GM Tech 2 or GDS2, or some advanced aftermarket scan tools.)

Scan Tool Commands That Help

• GM Tech 2 / GDS2: Immobilizer Data Display — Use this function to view the status of the Pass-Key III system. A key parameter to watch is 'TDM Transponder Key' or 'BCM Key Part Number'. It should change from 'Not Present' to 'Present' or display a key number when a valid key is turned in the ignition. If it remains 'Not Present' with all keys, it points to a faulty exciter coil or wiring.
• GM Tech 2 / GDS2: Programming / Immobilizer Learn — This function is required after replacing the BCM or ignition lock cylinder. It is also used to add new keys to the system. The tool guides the technician through the security relearn process, which is more reliable than the manual 30-minute procedure.

Wiring & Ground Locations

• BCM (Body Control Module) — Located below the left side of the dashboard, to the left of the steering column.. The BCM houses the Theft Deterrent Module (TDM) logic for the Pass-Key III system. All signals from the key's transponder are processed here. Poor connections at the BCM connectors can cause a B3055 code.
• BCM Connector C1 (Black, 52-Pin) — At the BCM, below the left side of the dash.. This connector contains the wiring for the ignition switch and starter relay control. Specifically, Pin 22 (Pink) is Ignition 1 Voltage and Pin 21 (Yellow) is the Starter signal.
• Theft Deterrent Exciter Module Wiring — The wires run from the ignition key cylinder down the steering column to the BCM.. A wiring diagram shows a Tan wire and a Black/White wire connecting the exciter coil (part of the ignition key cylinder) to the BCM. These wires carry the signal from the key; a break or short in this harness will directly cause code B3055.
• Ground G201 — On the left side of the dash support beam, above the BCM.. This is a primary ground point for many instrument panel components, including the BCM. A loose or corroded G201 can cause intermittent BCM operation and lead to various electrical faults, including security system errors like B3055.

Real Owner Repair Stories

• YouTube channel 'Repairs and Rides' (2007 Chevrolet Uplander) — No crank, no start. All lights and horn worked, but the engine would not turn over.
  ❌ Tried (didn't work) Replacing the starter motor (it was brand new)., Checking the ignition switch., Checking the neutral safety switch., Checking for power at the starter relay; found no ground signal to activate the relay.
  ✅ What actually fixed it The main battery ground terminal was corroded and not providing a sufficient ground for the engine, even though other accessories had power. After cleaning the ground wires and replacing the terminal, the starter relay received its ground signal and the vehicle started normally.
• YouTube channel 'ADD AUTOMOBILE SERVICES' (2013 Chevrolet Equinox (similar GM PK3+ system)) — Intermittent no-start with security light on and code B3055 stored.
  ❌ Tried (didn't work) Using the original key, which would sometimes work and sometimes fail.
  ✅ What actually fixed it The technician determined the original key's transponder was failing intermittently. Using a VVDI Key Tool, they cloned the data from the failing key onto a new 'super chip' and placed that new chip inside the original key fob. This provided a reliable signal and resolved the no-start condition.

OEM Part Supersession History

• 88964357, 15216929, 19149940 → 15795321 — Part consolidation and potential design updates by General Motors over the years.
  Heads up: The current part number, 15795321 (also sold as ACDelco D1462G), is the correct service replacement for the listed predecessors.