The 3.5L (VIN H) engine's unique ignition system has the ignition coils directly over each plug. No spark plug wires are used.
If a coil is replaced on any of the 3.1L, 3.4L or 3.8L engines, it may not be numbered, as is the factory coil. For this reason it is imperative that you label all wires before disconnecting any of them. Also, before removal, compare the current wiring with the accompanying illustrations.
The firing order for the 3.1L VIN M, 3.4L VIN E, 3.4L VIN X and 3.5L VIN H engines is 1-2-3-4-5-6. The right bank cylinders are on the cowl side (rear) of the engine compartment and are numbered 1,3,5, left bank cylinders on the front side of the vehicle, are numbered 2,4,6.
The firing order for the 3.8L VIN K and 3.8L VIN 1 engines is 1-6-5-4-3-2. Starting at the front of the engine, cylinders in the left bank are numbered 1,3,5 and cylinders in the right bank are numbered 2,4,6.