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The GM Waste-Spark Coil Pack: 2026 Working Spec

If you wrench on a GM 60-degree V6, you already run this layout: three coils, six cylinders, one coil firing two plugs at once. Each coil pairs with two cylinders through the Delphi-designed Ignition Control Module (ICM), and the system talks over legacy SAE J1850 VPW Class-B OBD-II.

The waste-spark ignition coil for Buick, Cadillac, Chevrolet, Oldsmobile & Pontiac replaces that three-coil pack on Buick Century and Regal, Cadillac DeVille, Chevrolet Impala, Monte Carlo, Camaro RWD, Oldsmobile Cutlass Supreme, and Pontiac Grand Prix — across 2.8L, 3.1L, 3.4L, and 3.8L (3800 Series I/II) displacements.

Two numbers carry the spec: primary resistance 0.5–0.9 Ω, secondary resistance 5,000–8,000 Ω. Stay inside those windows and the ICM drivers see predictable current.

Fast answers before you order

• CAN-bus 3.0 compatible in 2026? Yes — the coil is passive and signal-protocol-agnostic; trigger integrity comes from the ICM, which stays backward-compatible with J1850 VPW under J2534 pass-through, so your scan workflow does not change.
• Engine coverage: Buick 2.8L/3.1L/3.4L/3.8L V6; Cadillac 4.5L/4.9L era swaps; Chevrolet 2.8L–3.8L V6; Oldsmobile and Pontiac 3.1L/3.4L/3.8L — all waste-spark 3-coil/6-tower DIS layouts.
• OEM cross-reference: GM 10489422, 10457077, 19005218; Delphi D555/D1998A; ACDelco DR39/D577.
• Replace it when: you see extended-cranking misfires off idle, heat-soak stumbles above 100°F ambient, or P1361/P1362 GM ignition-control voltage faults.

Built for Hotter 2026 Engine Bays

Underhood thermal loading keeps climbing as downsized turbocharged GM variants bleed heat into adjacent V6 bay space, and these transverse compartments routinely exceed 230°F under heat soak. This coil answers with a glass-fiber-reinforced PBT polymer housing and vacuum-encapsulated secondary windings that block dielectric breakdown — the primary failure mode in waste-spark systems.

Shop rule of thumb: each tower fires twice per 720° crank rotation, doubling field-collapse stress versus coil-on-plug. Coils age on heat, not just miles — resistance drift shows up hot long before it shows up cold.

What changed versus the original Delphi D555

• Primary-resistance tolerance tightened to ±0.1 Ω, cutting the ICM current-draw variance that triggers intermittent P1350/P1362 fault codes.
• Nickel-plated primary terminals resist galvanic corrosion from ethanol-blended fuel vapor.
• High-temp silicone tower boots preserve secondary isolation above the 392°F flash points measured on Series II 3800 exhaust manifolds.

2026 compliance baseline

The unit meets C.A.R.B. emissions-adjacent Executive Order expectations, FMVSS-aligned safety norms, and UL94 V-0 flame-rated PBT housing standards — the housing will not feed a fire, and it survives sitting next to a Series II 3800 exhaust manifold.

DTC Fault Mapping: Fix the Right Part First

P0300–P0306 — random and cylinder-specific misfires

Check coil-pack tower carbon tracking, cracked PBT housings, or imbalance across paired cylinders. P0302 plus P0305 together points at one shared coil failure — those cylinders ride the same tower pair.

P0351–P0354 — ignition coil A/B/C/D primary/secondary circuit

Measure primary resistance at the ICM harness connector: target 0.5–0.9 Ω. Then measure secondary resistance tower-to-paired-tower: target 5,000–8,000 Ω.

P1350–P1362 and P1374 — control-side faults

P1350–P1362 are GM-specific ignition-control and bypass-monitor faults: verify ICM ground integrity, coil-to-ICM dwell timing, and a clean 5V reference from the PCM. P1374 means lost low-resolution 3X crank signals from the ICM — often blamed on the coil when the true fault is harness chafe or a failing ICM.

Technical Data Backbone

Every number below comes from the published spec for this coil pack — use it to verify a part, a return, or a bench test.

Bench Test and Replacement Strategy

Multimeter method — no specialist tools

Primary side: probe the two ICM connector terminals under the coil on the 200 Ω range — target 0.5–0.9 Ω. Secondary side: probe the paired high-tension towers on the 20k Ω range — target 5,000–8,000 Ω.

Any open-loop reading fails the coil on the spot. So does secondary drift above 9,500 Ω after heat cycling — a unit that drifts is a replacement candidate even though it passed cold.

Replace the ICM at the same time?

Above 100,000 miles, yes. These GM DIS systems fail as an ecosystem: a weakened coil raises ICM current demand, which accelerates ICM driver failure, which cascades into P1350/P1362 codes. New coil plus fresh ICM restores 2026-spec dwell timing and ignition energy.

Finish the job with matched parts

• Other GM platforms on the lift? This 6-piece ignition coil and G-Power spark plug set for Chevy Trailblazer, GMC Canyon and Buick covers secondary-side work in one order.
• Running a 2013–2019 Cadillac ATS 2.0L or 2017–2020 Buick Envision 2.5L L4? Those are coil-on-plug engines — order the ECCPP 4-coil set for the ATS 2.0L and Envision 2.5L L4 instead of this waste-spark pack.
• Anything else in the ignition circuit: start from the Koeep Ignition Systems & Components catalog and filter by platform.

Order With Backup: RFQ, Email, WhatsApp

Working other systems on the same car? The Chevrolet HHR SS 2.0L fuel pump 2026 buyer's guide applies the same spec-plus-DTC format to fuel delivery, so you keep one workflow across the vehicle.

FAQ — 2026 Failure Signatures and Field Fixes