So, I’ve got a 2012 JK and about a month ago, these pesky codes popped up. I took it to the dealer, and they ran diagnostics and replaced the Cam and Crank sensors, costing me a whopping $800. Now, fast forward a week, the car was running fine, but the codes are back, and my Jeep went into limp mode. It takes forever to start, and no matter how many times I clear the codes with my scanner, they just keep coming back.
I’ve been scouring this forum, and there are so many suggestions – it’s overwhelming. I even tried replacing the spark plugs, but no luck. Any other troubleshooting ideas? I’ve heard something about checking the ASD relay. My battery’s brand new, so I don’t think that’s the culprit either. If anyone could lend a hand, I’d really appreciate it.
Alright, so both the knock sensor (P0330) and crank sensor (P0335) are tied to the PCM through this harness, called C2, that basically loops around the engine from the driver’s side to the passenger’s side. This harness connects to various components like the coils, injectors, and sensors.
I have a hunch that there might be a faulty wire or connection somewhere in that harness. First things first, check to ensure the pins are fully extended and straight in the connector on top of the engine, and then do the same at the PCM. If the pins look good, it’s time to break out the ohm meter and start testing each wire individually. Make sure you get a solid connection at each end of the wire.
Given that the issue happens right away, there might be a break in the wires. Start with testing the short harness, which isn’t too pricey to replace if needed, and then move on to the long harness, which unfortunately costs a pretty penny if it needs replacing.
In my experience with my 2012, I had a faulty wire in the long harness that controlled one of the coils. To fix it, I spliced in a new wire directly from the PCM connector to the coil, ensuring it was the same length to maintain consistent resistance. It might have been a bit over the top, but I wanted to be thorough given how the computer manages things.
I’ll share the engine wiring diagram with you, which should make things clearer. It outlines wire sizes, colors, and pins. The connections can seem tricky at first, but once you get the hang of it, it’s not too bad. Just remember that the numbers on the right side of one page correspond to the numbers on the left side of the next page, going from page 1 to 5, and then vice versa.
I see you’re frustrated with your 2012 JK Wrangler acting up and showing error codes. You’ve tried fixing it and changing some parts, but the problem sticks around. Here are some tips that might help:
Check the ASD Relay: The ASD relay, which controls automatic shut down, often causes electrical issues in Jeeps. It can lead to problems like stalling or slow starts. Look up guides online or in a Jeep manual to test and swap out this relay.
Scan the Codes Again: Even if you’re erasing the codes with your scanner, it’s crucial to know what they are. These codes point to specific issues, aiding in diagnosis. Consider taking your Jeep to a specialist or dealership to get the codes scanned for more insight.
Explore Other Possible Causes: Several other factors could trigger your Jeep’s limp mode, like a damaged throttle position sensor, faulty MAP sensor, or transmission issues. Without knowing the exact codes, it’s hard to pinpoint the root cause.