B3055 on 2007 Saturn ION: Causes for No-Start and Security Light Fixes

What's Unique About the 2007-2007 Saturn ION

The 2007 Saturn ION uses GM's Passkey III+ (PK3+) immobilizer system, which relies on a transponder chip inside the key that is passively powered by an exciter coil in the ignition lock housing. This is a common system for GM cars of this era, including the Chevrolet Cobalt, Pontiac G5, and Chevrolet HHR, which all share the same Delta platform and experience this identical issue. The primary failure point is often not the key itself, but the components within the steering column responsible for reading it. This is different from the older 'Passlock' system used on some other GM vehicles, which used a magnet in the lock cylinder and a Hall-effect sensor in the housing, rather than a transponder chip in the key.

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 turn over
• Engine starts briefly then immediately stalls
• Security indicator light is illuminated or flashing on the dashboard.
• Intermittent no-start condition that may seem random
• A 'click' sound from the ignition, but the starter does not engage.

Most Likely Causes

1. Faulty Ignition Lock Cylinder / Housing 🔴 High Probability The exciter coil (antenna) that reads the key's transponder is housed with the ignition lock cylinder. This component is a known high-failure point on many GM Delta platform vehicles from this period, including the ION, Cobalt, and HHR, due to heat cycles and wear causing the coil or its fine wiring to fail.
   How to confirm: If a spare key and RFI elimination don't solve the issue, the lock cylinder is the prime suspect. A professional scan tool can monitor the 'TDM Transponder Key' data parameter in the BCM; if it reads 'Not Present' or 'No Key Detected' with a known-good key, the reader (exciter coil) has failed.
   Typical fix: Replace the ignition lock cylinder and perform the 30-minute security relearn procedure. This part contains the reader that communicates with the key. Common part numbers include Dorman 924-718 🎬 Watch: Step-by-step guide to removing the ignition lock cylinder and ACDelco 20869121.
   Est. part cost: $50-$150
2. Faulty or Damaged Ignition Key 🟡 Medium Probability The transponder chip embedded in the plastic head of the key can be damaged from drops, water exposure, or simple electronic failure over time. The key's plastic housing can also crack, causing the chip to fall out or shift position.
   How to confirm: The easiest way to confirm is to try starting the vehicle with a known-good spare key. If the spare key works consistently, the original key is faulty. A locksmith or dealer can also use a tool to test if the key is emitting a transponder signal.
   Typical fix: Replace the faulty key. A new key must be cut to match the original, then programmed to the vehicle. If you have one working key, you can often program a third key yourself in seconds. If all keys are lost, the 30-minute relearn procedure is required.
   Est. part cost: $70-$200
3. Radio Frequency Interference (RFI) ⚪ Low Probability As noted in GM TSB #PIC5650M, RFI can disrupt the low-frequency signal between the key and the reader coil. This is especially common with aftermarket electronics like phone chargers, dash cams, or having multiple RFID-enabled keys (other car keys, office access cards) on the same keychain.
   How to confirm: Remove all other keys, fobs, access cards, and aftermarket electronics (especially anything plugged into the 12V outlet) from the vehicle and keychain. Try starting the car with only the single ignition key. If it starts, RFI was the issue.
   Typical fix: Keep other RFID-enabled cards and powerful electronic devices away from the ignition key when starting the car.
   Est. part cost: $0

Rare But Worth Checking

• Wiring Harness Damage: The wires running from the ignition lock cylinder to the Body Control Module (BCM) can become chafed, pinched, or broken within the steering column from tilt-wheel adjustments or simple vibration over time. A visual inspection of the harness where it passes contact points is the first step.
• Faulty Body Control Module (BCM): While rare, the BCM itself can fail. This is typically the last item to suspect after all other possibilities (key, lock cylinder, wiring) have been ruled out. A failed BCM will usually present with other bizarre electrical issues as well. Replacement requires professional programming.

Diagnosis Steps

1. Scan for codes. Confirm B3055 is present and check for other related security codes like B3060, B3935, or B2955.
2. Try a spare key. This is the fastest and easiest way to rule out a bad key.
3. Eliminate Radio Frequency Interference (RFI). Remove all other keys, fobs, phone chargers, and aftermarket electronics from the car and try starting again.
4. Attempt the Security Relearn Procedure. Turn the key to 'ON' (not 'START') and wait for the security light to turn off (approx. 10 minutes). Turn the key off for 5-10 seconds. Repeat this process two more times for a total of three cycles (about 30 minutes). On the fourth attempt, the car should start. This procedure is necessary after replacing components and can sometimes resolve temporary glitches.
5. Inspect the wiring. Visually check the wiring harness connection at the base of the ignition lock cylinder and along the steering column for any signs of damage, chafing, or looseness.
6. If the above steps fail, the most likely cause is a faulty ignition lock cylinder. Replace the cylinder and perform the relearn procedure again.
7. If a new lock cylinder and relearn procedure do not fix the issue, the problem may lie in the BCM or the wiring harness, which requires more advanced diagnostics with a multimeter or professional scan tool.

Parts You'll Likely Need

• Ignition Lock Cylinder with Housing (OEM #20869121) — This assembly contains the exciter coil (reader) that communicates with the key's transponder. It is the most common hardware failure for code B3055 on this platform.
  Trusted brands: ACDelco, Dorman, Standard Motor Products (SMP)
  OEM price range: $60-$100
  Aftermarket price range: $50-$80
• Transponder Ignition Key (OEM #25832354 (PK3+ Key Blank)) — If a spare key works, the original key's internal transponder chip has failed. A new key is required.
  Trusted brands: ACDelco, Strattec
  OEM price range: $80-$150
  Aftermarket price range: $40-$90

Related Codes That Often Appear With This One

• B3060 — This code for 'Unprogrammed Key Transponder' often appears with B3055, as the system may detect a key but be unable to read or validate its programming.
• B3935 — Means 'Transponder Authentication Failed' and can be set during the same fault event where the key's signal is not properly received or authenticated.
• B2955 — This code for 'Security Sensor Data Circuit Malfunction' can appear alongside B3055, pointing more specifically to an electrical issue in the circuit between the exciter coil and the BCM.

Technical Service Bulletins (TSBs) & Recalls

• PIC5650M: Addresses intermittent no crank, no start, or start stall concerns with the security light on, specifically mentioning DTC B3055 and the potential for Radio Frequency Interference.
• 07-08-49-020 (and its revisions): While not directly for B3055, this TSB family explains how GM vehicle odometer and security information is stored and programmed in modules like the BCM, which is relevant when replacing components related to the anti-theft system.

Platform-Specific Known Issues

• The provided TSB #PIC5650M confirms that intermittent no-crank or start-stall conditions with the security light and code B3055 are a known issue for this vehicle family.
• Owners on forums like SaturnFans.com and CarTalk Community frequently discuss this exact B3055 no-start issue, with many confirming the fix was replacing the ignition lock cylinder and performing the 30-minute relearn.

Mechanic-Grade Diagnostic Values

• Theft Deterrent Module (TDM/BCM) Ground Circuit Resistance — expected: Less than 10 ohms. Failure: A value greater than 10 ohms indicates high resistance or an open in the ground circuit, which can cause communication failures.
• Theft Deterrent Module (TDM/BCM) Signal Circuit Voltage (Ignition ON, module disconnected) — expected: Less than 1 V. Failure: Voltage greater than 1V indicates a short to voltage on the signal circuit.
• Theft Deterrent Module (TDM/BCM) Signal Circuit to Ground Resistance — expected: Infinite resistance (OL). Failure: Any reading less than infinite (OL) indicates a short to ground on the signal circuit.

Hidden / Shadow Codes Worth Checking

• B3055 00: The '00' is a symptom byte for 'No Sub Type Information'. This means the base DTC text provides the complete description of the failure, and no further detail is available from a sub-code. (see via Visible on dealer-level scan tools like a GM Tech2 or GDS2, or some advanced aftermarket scan tools.)

Scan Tool Commands That Help

• GM Tech2 / GDS2: Immobilizer Data Display — Use this to monitor the 'TDM Transponder Key' or similar parameter. It should change from 'Not Present' to 'Present' when a valid key is inserted and turned to ON. If it remains 'Not Present' with a known-good key, it points to a failure in the reader coil (ignition lock cylinder) or its wiring.
• GM Tech2 / GDS2: Immobilizer Learn / Add Key — This function is required to program new keys to the vehicle's BCM after replacing a key or the BCM itself. It can also be used as a diagnostic step to rule out a simple programming glitch.

Wiring & Ground Locations

• G203 — Behind the lower left side of the dash, to the left of the steering column.. This is a major interior ground point that provides the ground path for the Body Control Module (BCM), instrument cluster, and the ignition lock cylinder control switch. A poor connection at G203 can cause intermittent communication issues with the anti-theft system, leading to a B3055 code.
• Ignition Switch Connector — At the ignition switch on the steering column, typically a Green 6-pin plug.. This connector contains the key wiring for the Passkey system. Specifically, Pin 5 (White wire) carries the MUX signal which is critical for the BCM to read the key's transponder data. A loose pin or damaged wire here will directly cause a B3055.
• BCM Connector C3 — At the Body Control Module, which is located at the lower center of the dash. It is a black 56-pin connector.. The wiring from the ignition lock cylinder's reader coil terminates at the BCM. A poor pin fitment or corrosion at this specific connector can interrupt the signal from the key, even if the key and lock cylinder are good.

Real Owner Repair Stories

• SaturnFans.com Forum (2007 Saturn ION) — No crank, no start issue with the security light on.
  ❌ Tried (didn't work) Replaced the ignition switch., Had the BCM 'repaired'., Installed a pre-programmed ECM.
  ✅ What actually fixed it The user was still diagnosing, but the advice given was to perform the 30-minute relearn procedure and to physically disconnect and reconnect the BCM and ECM connectors multiple times to scrape away potential corrosion on the pins, as this was a likely cause after replacing all major components.

OEM Part Supersession History

• Unknown → 20869121 — This is the current GM Genuine / ACDelco part number for the ignition lock cylinder assembly that fits the 2007 Saturn ION.
  Heads up: This part is sold as an uncoded cylinder and requires programming/special setup procedures (the 30-minute relearn) after installation to be learned by the vehicle's BCM.