Chrysler 300S Rear Bumper Schematic Diagram 2018 Exploded View Parts Guide

2018 chryslerbl 300s rear bumper schematics diagram

For precise structural repairs, start by obtaining the officially sanctioned OEM repair manual–specifically section 8-04 (Exterior Rear Fascia). This document includes exploded-view schematics, fastener torque specifications (e.g., 89 in-lbs for lower mounting bolts), and adhesive application zones (3M PN 08115 recommended). Local dealership repair centers maintain digital archives, while third-party aggregators like Mitchell1 or ChiltonDIY provide downloadable PDFs with bookmark-indexed diagrams.

If aftermarket solutions are required, confirm compatibility with part number 68037343AA–this denotes the factory assembly, including integrated sensor cutouts (blind-spot radar if equipped). Reverse-engineered diagrams often mislabel connector pinouts or omit reinforcement brackets; verify via cross-reference with Chrysler’s Tech Authority portal before fabrication.

For disassembly, note the six concealed Torx T20 fasteners behind the lower valance and dual alignment clips at the quarter-panel junction–removal sequence begins with disconnecting the wiring harness (locking tab release) followed by sequential bolt removal. Non-OEM aftermarket replacements may require trimming or drilling for proper alignment; measure twice using calipers (±0.5mm tolerance) before modification.

Technical Breakdown of the Chrysler Luxury Sedan Rear Fascia Assembly

Locate the retaining clips at positions C24, D17, and E9–these secure the lower valence to the quarter panel subframe. Apply 8–12 Nm torque in a diagonal pattern to avoid warping the aluminum backing plate. The factory schematic labels these fasteners as “T30 Torx,” but aftermarket replacements often require a metric M8×1.25 thread with a flanged head; verify thread pitch before installation. Sony XAV-AX5500 wiring harness connectors for the reverse camera integrate at snap-point F3; ensure the gasket sealing ring (P/N 05184666AA) is seated before mating the harness.

Structural Reinforcement Points

Reinforcement bracket BR-789 (OEM ref. 68108432AC) interfaces with the crush can via four 6.35 mm shear pins–replace these with hardened 1018 steel equivalents if towing exceeds 1,500 lbs. The upper support beam (P/N 05094587AD) features a damping pad at its centerline; omit lubrication here to maintain OEM noise suppression properties. When removing the assembly, disengage the fog lamp housings first by rotating the bayonet mounts 45° counterclockwise–force applied without rotation risks fracturing the polycarbonate lens.

For collision repairs involving the lower impact absorber, prioritize alignment of the energy-absorbing foam (P/N 68039502AA) with the factory mold seam lines. Misalignment by more than 3 mm reduces crash energy dissipation by 18%, per IIHS low-speed impact tests. The integrated parking sensor array (Bosch 0265009366) requires recalibration if removed–use Chrysler Tech Authority scan tool v12.2 or later, targeting sensor offset values of 0.0 ± 0.5° for azimuth and 1.0 ± 0.2° for elevation.

Fastener Positions and Attachment Zones for the Sedan’s Lower Tail Assembly

Begin removal by detaching the eight push-pin clips securing the underside cover across the apron; these are spaced at 150 mm intervals along the black plastic trim edge. Locate the dual 10 mm hex bolts anchoring the inner reinforcement panel to the chassis rails–one positioned 220 mm inward from each quarter-panel seam–and remove them first to prevent alignment binding. Beneath the exhaust cutout, a set of three T30 Torx screws hold the diffuser mesh in place; these must be unscrewed counterclockwise before the main fascia can pivot downward.

Mounting Point Fastener Type Quantity Torque Spec (N·m)
Fascia upper tabs M6 flange bolt 4 12–15
Inner reinforcement to frame M8 hex bolt 2 25–28
Diffuser to fascia T30 Torx 3 5–7
Apron underside cover Plastic push-pin 8 –

Detailed Guide to Detach the Sedan’s Lower Rear Assembly

Disconnect the negative battery terminal to eliminate electrical risks before touching any clips or fasteners. Locate the access panels inside the trunk behind the left and right taillight housings–remove the plastic covers by prying the four corner tabs with a trim tool. Unplug the wiring harnesses for the backup sensors and parking aid modules by pressing the release tabs and pulling straight out to avoid damaging the connectors.

  • Torx T25 driver releases the two bolts securing each side of the composite shell to the chassis rails–position a jack stand or hydraulic lift under the middle section to prevent sagging once freed.
  • Six 10mm bolts hold the underside valence to the frame; remove them from the wheel wells first, then slide the valence downward to clear the exhaust tips.
  • Pop the retaining clips along the top edge of the shell using a flathead screwdriver–insert between the body seam and twist to release without cracking the paint.

Slide the entire assembly rearward approximately 8 cm until the locator pins disengage from the unibody slots. Tilt the lower lip upward to clear the tow hitch receiver if installed. Support the weight evenly across two people or a spreader bar to prevent bending the aluminum reinforcement beam embedded in the structure.

Inspect the mounting points for rust or wear–clean any corrosion with a wire brush and apply dielectric grease to the chassis rails before reinstalling. Label all removed fasteners and sensor plugs with masking tape to simplify reassembly. Store the detached unit on padded blocks to prevent scratching or distortion.

Electrical Integration in Vehicle Rear Fascia Systems

Begin by disconnecting the negative battery terminal before handling any wiring to prevent short circuits or sensor damage. The harness for the rear assembly typically includes connections for parking sensors (if equipped), reverse lights, and trailer wiring modules. Locate the central junction under the trunk panel–this is where primary wiring splits into sub-harnesses. Use a multimeter to verify continuity on each pin: rear parking sensors (if present) operate on a 5V reference signal, while reverse lights require 12V. Corrosion on connectors is a common failure point; apply dielectric grease after cleaning terminals with a wire brush.

Key connection points:

  • Parking sensor harness (if applicable): Pinouts vary by model year, but expect 4-8 wires per sensor (power, ground, signal, and sometimes a shield). Sensor color codes often follow:
    1. Black/yellow: 12V power
    2. Brown: Ground
    3. Blue/white or violet: Signal output

    Test each sensor’s resistance–values should range between 200–600 ohms. A reading outside this range indicates sensor failure.

  • Reverse light wiring: Two thicker gauge wires (typically red and black/red) deliver power from the main harness. Probe the red wire with the ignition on and transmission in reverse–voltage should read 12V. If not, inspect the reverse light switch or fuse #28 (10A).
  • Trailer module (optional): Look for a 7-pin connector near the fascia’s lower valence. The pin layout follows SAE J560 standards:
    1. Yellow: Left turn/brake
    2. Green: Right turn/brake
    3. Brown: Tail lights
    4. White: Ground
    5. Blue: 12V auxiliary
    6. Red: Battery power
    7. Black: Reverse lights

    Ensure the module grounds to the chassis; a loose ground causes intermittent trailer light failures.

For sensor replacement, match part numbers precisely–aftermarket units often lack OEM calibration. The ECU expects specific voltage thresholds (e.g., 0.5V–4.5V for distance readings). Incorrect sensors trigger false parking warnings. When reinstalling the harness, secure it with cable ties every 15 cm to prevent chafing against the fascia’s metal substructure. Route wiring away from sharp edges and heat sources like exhaust components.

Final verification steps:

  1. Reconnect battery and cycle ignition.
  2. Engage reverse to test lights and sensors.
  3. Use a diagnostic tool (e.g., wiTECH) to check for DTCs–clear any false codes generated during disassembly.
  4. Visually confirm no wires fray against moving parts (e.g., trunk lid hinges).

Missed steps risk water intrusion into connectors, leading to permanent ECU damage. Always replace grommets if cracked or hardened.

OEM Component Breakdown and Genuine Part Identification

Replace damaged sections with exact OEM specifications listed under Mopar catalog number 68043027AC for the lower valence assembly–includes integrated fog lamp housings and sensor brackets. Align the upper impact beam (part #68156539AB) with the factory pre-drilled mounting points (5 mm tolerance) before securing with Torx T30 fasteners; third-party substitutes may disrupt adaptive cruise alignment. Verify ABS module compatibility when sourcing the wiring harness (PN 68302166AA) to prevent false collision warnings.

Sidemarker lenses (05186088AA) require UV-stable polycarbonate; aftermarket units often lack integrated reflectors, reducing DOT compliance. Install the exhaust finisher (PN 68043028AD) with the included stainless-steel clamp kit–alternative clamps may corrode within 18 months in high-salinity environments. The parking aid cameras (68197338AA) necessitate recalibration after installation; refer to TechAuthority bulletin 23-008 for targeting grid coordinates.