Like many DIY car enthusiasts, I’m familiar with using an Obd2 Jumper Wire to pull diagnostic codes. When the “D” indicator on my 2008 Honda Element (with a modest 78k miles and a vibrant orange paint job) started blinking, I knew it was time to investigate. Online forums pointed towards using a jumper wire to check for transmission codes, a method I’d successfully used before on other vehicles. I consulted resources like Flashing “D” light – how to solve and D light is blinking for no apparent reason NO CODES for guidance on using an OBD2 jumper wire for Honda diagnostics.
However, in my slightly awkward upside-down and backwards position peering at the OBD2 port, I made a critical error. Instead of correctly bridging pins 4 and 9 as instructed for retrieving codes, my jumper wire mistakenly connected pins 5 and 16. It was a mirror image mishap, jumpering the wrong pins entirely. For those unfamiliar, here’s an image showing the correct OBD2 jumper wire placement for this procedure, as shown in one of the forum videos I referenced:
Consulting a common OBD2 pinout guide afterwards confirmed my blunder. I had inadvertently connected pin #16, which carries the +12V battery voltage, directly to pin #5, the Signal Ground. A classic short circuit scenario through my OBD2 jumper wire.
Unaware of the potential problem at the time, I corrected my mistake, properly jumpering pins 4 and 9 this time. Success! I retrieved code 26, indicating a faulty 3rd clutch oil pressure switch – helpful information indeed.
However, my sense of accomplishment quickly faded. Upon starting my Honda Element to test drive, I discovered a range of electrical accessories were no longer functioning. It became clear that my brief OBD2 jumper wire short circuit had more serious consequences than just a misread code.
Frustratingly, after checking all the usual fuse locations, I couldn’t find any blown fuses. This led me to believe the issue might be more complex than a simple fuse replacement.
Here’s a breakdown of what’s working and what’s not after my OBD2 jumper wire incident:
Working Accessories:
- External lights: headlights, turn signals, brake lights, reverse lights
- Rear hatch dome light
- 12V Accessory socket in the passenger dash
- Power windows
- Power mirrors
Non-Working Accessories:
- Radio
- Dome light (only works with key in the ON position now)
- Power locks exhibiting strange behavior:
- Key ON: Unlock button on door panel works; Lock button does not.
- Key ON: Manually pushing down the lock knob on the driver door locks all doors.
- Key OFF: Lock buttons on door panel are completely unresponsive. Manually pushing the lock knob on the driver door only affects that door, not others.
- Remote key fob: No functions work (lock, unlock, panic).
- Cruise control main switch: The on/off button near the driver’s left knee no longer illuminates when pressed.
- OBD2 port itself: My scanner now fails to connect. Checking with a multimeter, there’s no voltage at pin #16 (12V power).
These symptoms eerily mirror those described in an old forum post https://community.cartalk.com/t/2004-honda-element-no-power-to-radio/92269 detailing similar radio and electrical issues in a 2004 Honda Element. Unfortunately, that original poster never updated with a solution.
So, the question remains: having potentially zapped the 12V power rail of the OBD2 port (pin 16) to signal ground (pin 5) with my ill-fated OBD2 jumper wire, where should I investigate next to diagnose this electrical problem? Could there be a fuse I’m missing, or is there likely a more serious component failure? Does anyone have access to a wiring diagram for a 2008 Honda Element that could help trace the power distribution for these affected accessories? Any guidance on troubleshooting this electrical mystery caused by my OBD2 jumper wire mistake would be greatly appreciated!
