🚨 Diagnostic Profile
Vehicle Make: Chrysler
Description: Cylinder 6 (IC) not toggling after enable command. This symptom is typically associated with the cylinder deactivation (Multi-Displacement System/Fuel Saver Technology) solenoid control circuit, the cylinder lifter oil supply, or related valvetrain components. Confirm the exact engine family (3.6L Pentastar, 5.7L HEMI MDS, or 6.4L) and model year in the service information before proceeding, as solenoid location, oil galley routing, and relearn procedures differ significantly by platform.
🚨 Repair Difficulty Tier
[Intermediate]
Diagnosis requires bidirectional scan tool access, live data monitoring, and oil pressure/flow verification at the lifter gallery. Repair may require intake manifold removal (Pentastar) or valve cover/rocker access (HEMI), which increases labor complexity and time.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
- Verify engine oil level, condition, and correct viscosity grade per service specifications; contaminated or low oil is the leading cause of MDS/lifter toggle failures.
- Scan all modules (PCM/ECM) for active and stored DTCs (e.g., P0022, P0353, P1494, or manufacturer-specific MDS/lifter fault codes) and record freeze frame data for the cylinder 6 event.
- Inspect the cylinder deactivation solenoid connector at the valve cover/cylinder head location nearest cylinder 6 (verify exact bank/position using the firing order diagram in service information) for corrosion, bent pins, or oil intrusion into the connector shell.
- Inspect the wiring harness between the PCM and the solenoid for chafing, heat damage, or pinch points near the valve cover or intake manifold mounting points.
- Check solenoid supply/control voltage at the harness connector using a digital multimeter against a known good ground with the key on, engine running; confirm the circuit receives commanded battery voltage or reference voltage per the wiring diagram.
- Inspect the valve cover area, oil control valve (OCV) screen/filter, and lifter galleries for oil leaks, sludge buildup, or debris restricting oil flow to the deactivation lifters.
Step 2: Diagnostic Verification
- Command the cylinder deactivation (enable) function with a bidirectional scan tool and monitor the commanded state versus the actual feedback state (oil pressure switch or lifter position feedback if equipped).
- Monitor live data for cylinder 6 misfire counters, MDS status PID, and oil control solenoid duty cycle; compare behavior against the other deactivation-capable cylinders during enable and disable commands.
- Perform a lifter oil pressure or oil flow test as specified in the service information, using the oil gallery test port or by installing a calibrated oil pressure gauge adapter at the main oil gallery or MDS solenoid mounting bore.
- Test the solenoid circuit resistance and continuity using a digital multimeter at the connector with the harness disconnected; compare readings against the specific resistance value published in the OEM wiring/component specification chart for that solenoid part number.
- Verify camshaft and crankshaft correlation using the scan tool relative compression or cam/crank sync PIDs, and check for any timing-related codes (P0016, P0017) that could mimic a lifter toggle fault.
- Confirm whether the fault follows the solenoid, the harness, or the lifter assembly by substituting a known-good solenoid only where service information authorizes component swapping for diagnostic isolation.
Step 3: Resolution & Reset Process
- Repair or replace the faulty component based on verification results: MDS/cylinder deactivation solenoid, a damaged harness section, the deactivating lifter assembly/lifter oil manifold assembly (LOMA), or an oil supply restriction component.
- Clear all DTCs and perform any required PCM relearn, adaptive reset, or crankshaft/camshaft correlation relearn procedure as defined in the OEM service information using a capable scan tool (e.g., factory diagnostic software or an equivalent OEM-level aftermarket scan tool).
- Road test the vehicle under the specific speed, load, and throttle conditions that trigger cylinder deactivation (typically steady-state cruise, light throttle) and confirm normal MDS/Fuel Saver toggle operation with no recurring codes.
- Recheck live data after the road test, confirming commanded vs. actual cylinder deactivation status matches and misfire counters remain at zero, then document all final readings on the repair order.
📦 Parts, Labor, and Budget Estimates
Required Components/Software:
- MDS/Cylinder Deactivation Oil Control Solenoid (cylinder 6 position) — OEM or OEM-equivalent part, verified by VIN and engine code
- Deactivating Lifter Assembly / Lifter Oil Manifold Assembly (LOMA) — required only if lifter is confirmed mechanically stuck via oil flow test
- Valve cover gasket set and/or intake manifold gasket set (consumed during access on Pentastar or HEMI platforms)
- Wiring harness repair kit (connector pigtail, terminals, heat-shrink splice) if harness damage is confirmed
- OEM-level diagnostic scan tool subscription or dealer programming session for PCM relearn/adaptive reset (if required by platform)
Average Component Price: MDS solenoid: $60–$150 each (part only); Lifter/LOMA assembly: $150–$400 per cylinder bank section depending on engine family; Gasket sets: $30–$90; Wiring repair kit: $20–$60; Dealer programming/relearn session (if independent shop lacks capability): $100–$180
Estimated Labor Hours: Diagnostic time (scan, live data, oil flow test, circuit testing): 1.0–2.0 hrs. Solenoid replacement only: 0.5–1.5 hrs depending on access. Lifter/LOMA replacement requiring intake manifold or valve cover/rocker removal: 3.0–6.0 hrs (HEMI 5.7L/6.4L typically on the higher end due to rocker arm and pushrod removal; Pentastar 3.6L requires intake plenum removal). PCM relearn/reset: 0.2–0.5 hrs. Total estimated shop time for full diagnosis and repair: 4.0–8.0 hrs depending on confirmed root cause and engine platform.