An ignition coil transforms voltage from the battery and turns it into energy the spark plug can use to…spark. Making it an essential component of the ignition system.
And for years, Volkswagen vehicles have had issues with ignition coil and connectors that fail, potentially leaving drivers stranded with a stalled out engine and no power steering or brakes.
Signs That The Ignition Coil Has Failed ∞
Honestly, it isn't hard to tell when an ignition coil is having problems. Let's just say when they fail, they don't do so in a subtle way.
Some of the most common problems include startup issues, loud engine cranks, backfires, hesitations, and increased risk of engine fires!
And then there's the whole misfire while driving scenario that can cut power to the engine, power steering, and power brake assist all at the same time.
Potential engine codes ∞
If an ignition coil fails it should trigger the check engine light and will likely result in error codes PO300, PO302 and PO304 depending on what cylinder is misfiring.
Why Are VW Ignition Coils Failing? ∞
VW uses a coil-on-plug design that, as the name suggests, has an ignition coil installed directly on top of each of spark plug. Unlike a system that uses a coil pack or distributer, this design increases the chances of a single ignition coil causing a whole lot of trouble.
The coils aren't exactly put in a position to succeed. According to some mechanics, the coils in VW engines are placed at the top of the engine and covered in a way that when the hot air from the engine rises it gets trapped. Almost creating an oven for the coils to bake in.
And like most things electrical, they don't take too kindly to heat as prolonged exposure makes the wires and seals brittle. Once the seals to sealing, it also introduces the chances of another nemesis doing damage – moisture.
The ignition coil connector is another area that can cause all sorts of problems. Anytime you go to service a coil or spark plug you need to deal with the connector which is known for easy-to-break tabs, easy-to-miss connections, and easy-to-rupture seals.
Complaints rise ∞
Around the beginning of 2003 VW started to see complaints about ignition coil failures spike, particularly in the 2001-2002 New Beetle, Golf, GTI, Jetta, and Passat.
VW issued a Customer Satisfaction Campaign (CSC) to "inspect the vehicles for any malfunctioning coil packs and to replace them at no cost to the consumer." Letters were sent to owners on June 6th, 2003.
Owners who had previously paid for ignition coil replacements were given options for reimbursements.
Replacement parts in short supply ∞
But it turns out a lot of owners were having ignition coil problems and when they all came to get their repairs, parts were in short supply.
At one point, the problem was so widespread that
replacement parts have been in short supply, some cars have sat for days or weeks.
Due to that limited supply, VW would only replace coils that had already failed. Although to their credit, the CSC was later revised to replace all ignition coil packs regardless of their performance.
Government Petitioned to Investigate Ignition Coil Issues ∞
Even the replaced ignition coils were having problems, and faced with the scary consequences and limited supply of replacement parts the government wa petitioned to investigate the issue by VW owner Ron Strickland.
Mr. Strickland said his 2002 Jetta has had several ignition coil and ignition wiring harness failures causing the vehicle to stall or suddenly lose power. He says he has been
involved in several near collisions to date as the problem usually occurs in heavy traffic or freeway driving and that the power steering and brakes weren't available when he needed them most.
The petition mentioned the 2000-2003 Jetta, Golf, and Passat, as well as the 2002 Jetta.
ODI says nope ∞
In August of 2005, the Office of Defects Investigation (ODI) responded to the petition saying the Volkswagen's CSC in 2003 was sufficient. Additionally, they believed the chances of a complete engine shutdown were "very small."
In view of the need to allocate and prioritize NHTSA's limited resources to best accomplish to the agency's safety mission, your petition is denied.
Eventually an investigation does happen ∞
However, several years later Volkswagen ignition coils did get an investigation when the National Highway Traffic Safety Administration (NHTSA) looked into ignition coil problems in 2002-2003 Passat following 16 reports of faulty ignition coils that either caused a fire or killed the power to the engine.
"ODI has received 11 complaints alleging that a fire started in the engine compartment of the vehicle that may be related to ignition coil failure, and 9 complaints of ignition coil failure that did not result in a fire.Reports state that the vehicle hesitated or lost power, and the check engine or dashboard lights illuminated.The vehicles were repaired by replacing the faulty ignition coil(s). Some of the complaints indicated that the ignition coils were replaced more than once."
Strangely, the investigation never resulted in a recall.