🚨 Diagnostic Profile
Vehicle Make: Chrysler
Description: No SKIM Bus Message Received. The Sentry Key Immobilizer Module (SKIM) is not communicating on the vehicle network, which can prevent engine start and related immobilizer functions.
🚨 Repair Difficulty Tier
Tier: [Intermediate]
Requires scan tool network diagnostics, bus voltage and continuity testing, and possibly security programming equipment.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
- Verify battery state of charge (minimum 12.4V resting, stable under cranking load) and inspect battery terminals, ground straps, and chassis-to-engine ground connections for corrosion or looseness.
- Inspect the SKIM connector and harness at the base of the steering column (most Chrysler/Dodge/Jeep platforms mount the SKIM to the steering column or key cylinder housing, directly behind or below the ignition switch) for corrosion, terminal pushback, or chafed insulation.
- Check the fuses and relays supplying ignition and accessory power to the SKIM in the Integrated Power Module (IPM) or Totally Integrated Power Module (TIPM), referencing the fuse box diagram printed on the underside of the fuse box cover or in service information for this specific platform and model year.
- Ask about recent wiring modifications, remote start installs, aftermarket alarm systems, or water intrusion near the steering column or kick panel areas, as these are common causes of bus disruption on these platforms.
Step 2: Diagnostic Verification
- Connect a compatible scan tool capable of full-system network diagnostics (factory-level tool such as wiTECH preferred for Chrysler security/bus faults) and check for U-codes (network/communication DTCs) and B-codes (body/SKIM-specific DTCs) across all modules, not just the PCM.
- Measure bus circuit voltage/activity (PCI bus or CAN bus depending on platform and model year) using a digital multimeter or scope, with the key in the ON position, and compare against known-good bus signal patterns per the service information network diagram for this specific platform.
- Check bus circuit continuity and resistance between the SKIM, PCM, and the diagnostic connector per the wiring diagram topology for this specific vehicle, looking for opens, excessive resistance, or unintended splices.
- Check for shorts to battery voltage or chassis ground on the network circuit, as a shorted bus wire will typically take down communication with multiple modules simultaneously, not just the SKIM.
- Confirm the SKIM has proper switched ignition power, constant battery power, and a clean ground at its harness connector using a multimeter referenced to a verified good ground point, per factory pinout documentation for this model and year.
Step 3: Resolution & Reset Process
- Repair or replace the faulty harness section, connector, or module as indicated by testing; prioritize wiggle-testing the column harness and SKIM connector since a high percentage of these faults are connector-related rather than SKIM failures.
- Clear all stored DTCs across all modules and perform a full network communication check to confirm no new or pending U-codes return.
- If the SKIM or PCM is replaced, perform the required Secret Key/PIN retrieval and SKIM-to-PCM re-synchronization (or full key relearn) procedure using a factory-level scan tool such as wiTECH, as aftermarket tools may not support full security module programming on these platforms.
- Verify engine start, confirm the Sentry Key indicator lamp cycles normally (solid then off, not flashing), and recheck for communication faults with a final full-vehicle scan after the repair.
📦 Parts, Labor, and Budget Estimates
Required Components/Software:
- SKIM module (if confirmed faulty, not just a communication fault)
- Steering column harness pigtail/repair connector or ignition harness repair kit
- Factory-level scan tool subscription (wiTECH or equivalent) for security module programming and PIN retrieval
Average Component Price:
- SKIM module: approximately $150–$350 (part cost only; does not include programming)
- Harness repair kit/connector pigtail: approximately $25–$90
- Dealer or locksmith SKIM programming/PIN retrieval fee: approximately $75–$200 if performed by a specialty locksmith or independent shop with security access; dealer programming may be bundled into labor
Estimated Labor Hours:
- Diagnosis (network/bus fault isolation): 1.0–2.0 hours
- Repair or replacement (harness repair or SKIM/column component replacement): 0.5–1.5 hours, more if steering column disassembly is required for access
- Programming and verification (SKIM/PCM sync, key relearn, post-repair scan): 0.5–1.0 hour