Diagnostic Digest Volume 3

It was a warm Wednesday morning and Native Californian Noah Waite had just opened the doors to his Hang-Ten Garage. Over the last 15 years, he had built up a solid automotive service business in the California coastal community of Huntington Beach, the unofficial “Surf City, USA”.

Munching on breakfast and sipping his chai latte with a light splash of cream, two pumps of caramel, and extra caramel drizzle, Noah surveyed the schedule for the day’s work. But his cognitive calculations were soon interrupted by the sound of a laboring Power Stroke Diesel.

Arriving in style (towed by a Ford), was a well-worn 2008 Dodge RAM 1500 Truck sporting 4WD and a 5.7L V8. Owner Lance Luken, a professional surfer (and recently acquired customer), had owned this truck since he bought it new. Although he had kept up on fluid changes, little else was done to maintain this vehicle, and it needed a lot of TLC.

The HEMI-powered hauler had several critical issues; the latest issue was a “cranks, but no-start.” Noah decided to start his diagnosis with the no-start.

Grabbing a scan tool, he wanted to verify that he could communicate with the PCM and pull any current codes. Upon communication he found the following:

Noah remembered hearing Lance say that the truck had been running rough for the last few weeks. The misfire code and Ignition Coil Secondary Circuit Code were not a likely reason for the no-start. The P0513 was the most likely cause. Noah knew that the SKIM (Sentry Key Immobilizer Module) had the power to prevent a start if the SKIM didn’t recognize the key or an actual theft attempt had occurred. Since this was California, thieves were too busy stealing full-size Chevy trucks to waste their time on a Dodge RAM. Something else was going awry with the Dodge RAM.

It was time for Noah to do some research. He suspected there may be a Technical Service Bulletin (TSB) relating to the P0513. He thought, “perhaps this is a known issue, and the manufacturer has developed a fix?” Unfortunately nothing was found in the TSB’s that related to this code. Looking up the P0513 in his service information gave him some items to check. This included communicating with the SKIM to determine the proper VIN is programmed, determining that there was no obvious damage to the ignition key, and verifying that no vehicle remote starters, alarms, or other devices were recently added that might be confusing the SKIM.

While inspecting the ignition key Noah noticed that everything on the keychain was graced with a patina that only years at the beach could produce. They all looked old – except for a gym membership electronic key. Noah recognized the key as a Radio-Frequency Identification (RFID) key which was similar electrically to the ignition key. He remembered reading years ago about a Honda driver that owned two Accords. The owner experienced occasional no-starts when they placed the keys from both cars on the same key ring.

It was worth a shot. Noah removed the gym key, turned the ignition key, and now the mighty HEMI roared to life.

A quick call to Lance confirmed that the RFID key was added yesterday. Noah explained the cause of the no-start and, given the modest amount of time needed to diagnose that issue, Lance gave the go-ahead to tackle the misfire and to also investigate a long-standing problem he had with refueling the truck.

The P2305 and P0302 both pointed to a problem with Cylinder 2. Unplugging the ignition coil made no change in engine operation, so the cylinder was not contributing to the power output. The #2 ignition coil had signs of severe overheating.

Noah found a verified repair for a similar code on ALLDATA’s Community. While that code, P2308, was for Cylinder 3, the diagnostic process was the same: check the circuit to the coil.

With the engine running and the coil still unplugged, Noah found battery voltage (B+) on the brown wire with the white stripe (BR/WT) at the two-pin coil connector. So far, working as intended by the MOPAR engineers. When checking the Coil Control – a dark blue wire with the tan stripe (DB/TN) – he found a constant path to ground and not the pulsed ground he expected to find.

 

He had to rule out the harness before going any further. After shutting down the engine and disconnecting the battery, he unplugged the C2 connector at the PCM and checked pin 9 (DB/TN) for continuity to ground. While the wire itself tested as "good", Noah determined the coil driver transistor in the PCM was internally shorted which caused a constant ground to be applied to the ignition coil, which, in turn, overheated it. Although the coil could have been the cause of the bad PCM, both the ignition coil and the PCM would need replacement to fix the misfire.

Lance mentioned that he was having problems adding fuel to the truck. The nozzle would click off several times while refueling and sometimes he would be hit in the face with splash of fuel worth $2 in California!

Noah’s additional research located a Stellantis/Fiat-Chrysler (FCA) TSB 14-003-14 which recommends replacement of the fuel filler tube to cure the refueling problems. The best part of the fix was that FCA will fix it at no charge to Lance; the service bulletin advised that this part has lifetime warranty coverage.

Lance authorized a replacement PCM and new ignition coil, curing the misfire. Two weeks later the local Chrysler, Dodge, Jeep, and RAM dealership replaced the fuel filler tube. Problems fixed.

The truck was ready to transport Lance and his boards to the beach, and Noah was able to get back to his regularly scheduled customers. Surf’s up!