B3055 on 2007-2012 Chevrolet Colorado: Passlock No-Start Causes and Fixes

What's Unique About the 2007-2012 Chevrolet COLORADO

The first-generation Chevrolet Colorado and its GMT355 platform mates (GMC Canyon, Hummer H3, Isuzu i-Series) are well-known for issues with the GM Passlock II anti-theft system. The design integrates the security sensor into the ignition lock housing, which is the most common point of failure, leading to the B3055 code and frustrating no-start situations. Unlike systems where a transponder chip is in the key itself, this system uses a magnet in the lock cylinder and a Hall-effect sensor in the housing, making the housing the critical component that fails.

Diagnostic Flowchart

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

Symptoms You May Notice

• Engine cranks but will not start
• Engine starts and immediately stalls
• Security light is illuminated or flashing on the dashboard.
• "Service Theft System" message on the instrument cluster.
• Intermittent no-start condition that may temporarily resolve after waiting 10 minutes with the key on.

Most Likely Causes

1. Faulty Ignition Lock Housing (Passlock Sensor) 🔴 High Probability → Shop Ignition Switch This is the most common failure point for the Passlock system on this platform. The internal sensor fails over time, sending an incorrect or no signal to the BCM. The wiring for the sensor consists of three thin wires (typically Yellow, Black, and White) that are known points of failure.
   How to confirm: Use a scan tool to monitor the Passlock sensor data while turning the key. An erratic or missing signal points to a bad sensor. One can also back-probe the yellow signal wire at the BCM to check for the correct voltage drop when the key is turned. If the signal is bad and wiring is confirmed good, the housing is the fault.
   Typical fix: Replace the entire ignition lock housing 🎬 See this video for a guide on replacing the lock cylinder., which contains the new sensor. This must be followed by a security relearn procedure. The most common replacement part is ACDelco D1462G or GM part 15822350.
   Est. part cost: $60-$110
2. Wiring/Connector Issue 🟡 Medium Probability The three small wires (Yellow signal, White power, Black ground) running from the ignition lock housing down the steering column can chafe, break, or develop loose pins at the BCM connector.
   How to confirm: Visually inspect the wiring harness from the ignition cylinder down the steering column. Check for continuity on all three wires and for shorts to ground or voltage on the signal wire between the lock housing and the BCM.
   Typical fix: Repair the damaged section of the wiring harness or clean/tighten the connector terminals at the BCM.
   Est. part cost: $5-$25
3. Worn Ignition Key or Lock Cylinder ⚪ Low Probability → Shop Ignition Switch While the key does not have a chip, a very worn key or cylinder can fail to properly rotate the magnet, causing the Passlock sensor to read incorrectly. On vehicles with a flip-key, not having the key fully extended and locked can also cause this code.
   How to confirm: Try a spare key. If the problem disappears, the primary key is the issue. Visually inspect the key for excessive wear. Ensure flip-keys are fully extended.
   Typical fix: Have a new key cut to the vehicle's code. If the cylinder is worn, it will need to be replaced along with the housing.
   Est. part cost: $15-$50

Rare But Worth Checking

• Radio Frequency Interference (RFI): GM has issued bulletins (PIC5650M, PIC5650B) noting that aftermarket electronic devices like phone chargers, LED lights, or even other key fobs with RFID chips can interfere with the security system's frequency, causing intermittent no-start issues and setting B3055. Before replacing parts, remove all aftermarket electronics and non-essential items from the keychain and re-test.
• Faulty Body Control Module (BCM): → Shop Body Control Module While rare, the BCM itself can fail. If the Passlock sensor signal and wiring are confirmed to be good, but the code persists, the BCM may be the culprit. This is an expensive last resort and requires programming by a dealer or a properly equipped shop.
• Low Battery Voltage: → Shop Vehicle Battery A weak or failing battery can cause a host of electrical issues, including causing the BCM to incorrectly flag a security fault. If the battery is below 12.4 volts, it should be charged and tested before proceeding with Passlock diagnosis.

Diagnosis Steps

1. Verify the complaint: Attempt to start the vehicle and observe for a crank-no-start or start-stall condition. Note the status of the security light.
2. Scan for Codes: Use a scan tool to confirm B3055 is present in the Body Control Module (BCM). Note any other related codes like B3060 or B3935.
3. Check for RFI: Remove all aftermarket chargers, devices, and extra keys/fobs from the vehicle and keychain. Try starting again.
4. Check Battery Voltage: Ensure the battery has a stable voltage above 12.4V. A weak battery can cause false security codes.
5. Try the Security Relearn Procedure: Attempt the 30-minute relearn procedure. This can sometimes resolve temporary glitches.
6. Inspect the Key: Try a spare key if available. Inspect the original key for significant wear. For flip-keys, ensure they are fully extended.
7. Test the Passlock Sensor Circuit: Access the three-wire harness from the ignition lock housing (Yellow, White, Black). Check for 12V on the white wire, good ground on the black wire, and a valid signal on the yellow wire with the key on. A scan tool with live data is ideal for monitoring the signal.
8. Replace Ignition Lock Housing: If the sensor signal is faulty and wiring is intact, replace the ignition lock housing (ACDelco D1462G).
9. Perform Security Relearn: After replacing the housing, you MUST perform the 30-minute security relearn procedure for the vehicle to recognize the new component and start. The procedure is: 1. Turn key to ON 🎬 Watch: A step-by-step walkthrough of the 30-minute security relearn procedure. (run). The security light will be on. 2. Wait ~10 minutes until the light goes out. 3. Turn key OFF for 5 seconds. 4. Repeat steps 1-3 two more times for a total of 3 cycles / 30 minutes. 5. The vehicle should now start.
10. Diagnose BCM: If all other steps fail, the Body Control Module (BCM) may need to be professionally diagnosed and possibly replaced.

Parts You'll Likely Need

• Ignition Lock Housing (OEM #ACDelco D1462G, GM 15822350) — This housing contains the Passlock sensor, which is the most common component to fail and cause code B3055.
  Trusted brands: ACDelco, Dorman
  OEM price range: $80-$110
  Aftermarket price range: $60-$90

Related Codes That Often Appear With This One

• B3060 — This code, 'Unprogrammed Transponder', often appears with B3055 as it relates to the same security system communication failure.
• B3935 — Another transponder circuit malfunction code that can be triggered by the same root causes as B3055.
• B2960 — A related Passlock code, 'Security System Sensor Data Incorrect but Valid', which can also point to a failing ignition lock housing sensor.

Technical Service Bulletins (TSBs) & Recalls

• PIC5650M: Mentions B3055 in the context of an intermittent no crank, no start, or start stall concern with the security light on, and suggests checking for Radio Frequency Interference (RFI).
• PIT5030E: While for other GM models, it notes that an intermittent no-crank with B3055 can be caused by a flip-key not being fully extended, which is relevant user-error information.
• 07-08-49-020H: A general bulletin about module programming that confirms the BCM stores critical vehicle data and requires specific procedures (like SPS) when replaced, which is relevant if the BCM is suspected.

Platform-Specific Known Issues

• The GM Passlock II system is notoriously problematic 🎬 Watch: How to perform a permanent Passlock system bypass. on this generation of Colorado/Canyon, with the ignition lock housing sensor being the primary weak point.
• Some owners opt to permanently bypass the system. One method involves cutting the Passlock signal wire (often the Yellow wire, but sometimes a White wire with a Blue stripe) after starting the engine. This disables the system but will leave the security light permanently on. Another method involves soldering a resistor with the correct value between the signal and ground wires to permanently mimic a valid key turn.
• Forum threads on 355nation.net and coloradofans.com are filled with owner experiences detailing this exact failure, with most confirming the ignition lock housing as the fix.

Mechanic-Grade Diagnostic Values

• Passlock Sensor Signal Wire Voltage (Key-On) — expected: Approx. 5.0V. Failure: Voltage is 0V or significantly different from 5.0V before cranking. When the key is turned to CRANK, this voltage should drop to a lower, stable value. An erratic or absent signal indicates a fault.
• Passlock Sensor Power Wire Voltage — expected: Approx. 12V (Battery Voltage). Failure: No voltage indicates a wiring or BCM power supply issue.
• Passlock Sensor Resistance — expected: Varies by vehicle (values near 14,000 Ohms have been observed). This is not a fixed value across all trucks.. Failure: The specific resistance value is less important than the change in voltage it causes on the signal wire. An open or shorted sensor is a definitive failure.

Scan Tool Commands That Help

• Tech2 / GDS2: Body Control Module > Module Setup > Program Key Fobs — While not a direct diagnostic for B3055, this path is used to access BCM security functions. A professional scan tool can also monitor the 'Passlock Data Voltage' live data PID to watch the sensor's signal in real-time, which is the primary diagnostic step.

Wiring & Ground Locations

• BCM Connector C1, Pin B10 — The Body Control Module (BCM) is located in the passenger kick panel area. C1 is one of the large connectors.. This is the pin for the Passlock Sensor Signal wire (typically Yellow). It should be back-probed here to verify the signal from the sensor is reaching the BCM.
• BCM Connector C2, Pin E9 — At the BCM in the passenger kick panel.. This is the pin for the 12V power supply to the Passlock sensor.
• BCM Connector C2, Pin E8 — At the BCM in the passenger kick panel.. This is the pin for the ground reference (low reference) for the Passlock sensor.
• SP-105 — Under the hood on the driver's side, near the battery and ABS module. It is a black plastic splice pack connecting multiple ground wires to a single chassis bolt.. This ground splice pack serves the Run/Crank relay, fuel pump, and EBCM. Corrosion here can cause intermittent no-start or electrical issues that could be misdiagnosed as a Passlock failure.
• SP-106 — Under the hood on the passenger side, behind the engine airbox.. This ground splice pack serves the HVAC control module and Data Link Connector (DLC). A bad ground here can cause a variety of strange electrical behaviors and communication issues with scan tools.

Real Owner Repair Stories

• Reddit user Deep_Assumption5406 (2012 Chevrolet Colorado) — Passlock system trips every morning, requiring a 10-minute wait with the key in the 'ON' position before the truck will start.
  ❌ Tried (didn't work) The owner was considering replacing the PCM or BCM.
  ✅ What actually fixed it The confirmed advice from an experienced user was to first try a new key. If that doesn't work, the problem is almost certainly the ignition switch/housing assembly. The BCM is rarely the fault unless many other unrelated electrical issues are also present.
• YouTube channel 'On The Brink' (Chevrolet Colorado (2004-2012 generation)) — Classic intermittent no-start with flashing security light (Passlock fault).
  ❌ Tried (didn't work) Waiting for the 10-minute timer to expire to get the truck started.
  ✅ What actually fixed it The owner performed a permanent bypass. After getting the engine to start and run, they located the Passlock signal wire under the dash (in this case, a White wire with a Blue stripe), cut it, and separated the ends. This permanently disables the Passlock system, allowing the truck to start every time, but leaves the security light illuminated on the dash.

OEM Part Supersession History

• 15822350 → 15822350 — This part number appears to be stable with no major supersessions noted. It is the primary OEM number for the ignition lock housing assembly that includes the Passlock sensor.

Model Year Variations Within This Range

• 2007-2012: The Passlock signal wire color may vary. While often described as a solid Yellow wire, some owner repairs have documented it as a White wire with a Blue stripe. Technicians should verify the correct wire at the BCM pin (C1, B10) before cutting or splicing for a bypass.