Naked Tree 2x4
NAXJA Forum User
- Location
- Florida
my obd-II tells me a code 76. fuel bypass pump or something and syas to take it to the shop. i dont want to do that. now what? anyone familiar with this?
JJacobs said:I don't have a diagram in front of me but I'd imagine there should be two keyed hot leads and a computer switched ground, then another power lead that's only hot when the relay fires up.
5-90 said:OBD-II codes can be read either as the SAE Standard directs (a letter and four numerical digits,) or with a two-digit manufacturer's code (like your code 76.) SAE allowed the manufacturers to use two-digit codes so that the flashin of the CEL/MIL could still be used to depict codes - the SAE standard codes require the use of a separate code reader. DTCs can also be portrayed using a hexadecimal numbering system (Base 16 - common in computers, uses 0-9 + A-F, or a digit span of 0-F) as well.
I've got a listing of OBD-II codes on my site (http://www.geocities.com/JeepI6Power/obd2.html for everyone to refer to, taken directly from Jeep FSMs (to reduce extraneous codes. I'm working in the SAE full listing, and it will be labelled as such.) There doesn't seem to be "DTC 76" until I refer to the hexadecimal numbers, when it becomes "Fuel System Rich" - meaning that the system keeps trying to correct "lean" and it doesn't get anywhere. This is a "hard" code, which will illuminate the CEL/MIL if set.
I hate to mention these people, but most of the "Chain" stores (like Autozone, or Advance Auto) have OBD-II readers they can use to retrieve the SAE DTCs gratis, and you can then have the code interpreted and get an idea to service your vehicle. Also, if you plan to keep the vehicle for a while, there are OBD-II readers well within reach of the typical hobbyist - down around $100-$150. Saves you a lot of running about... I'd get one. (I need to anyhow - we just got a 2005 Verona for her to drive about in, and it's OBD-II.
OBD-II was used in the XJ beginning in the 1996MY. Should you have a 1991-1995XJ, you actually have OBD-I - which is a different coding system (since that was set by the manufacturers, not SAE.) In OBD-I, DTC 76 denoted trouble with the Fuel Pump Ballast Resistor Circuit - and it was a "soft" code (did not illuminate the CEL/MIL.) That's an easy fix, and most ballast resistors run about five bucks. OBD-I readers tend to be a little cheaper as well - ~$100 - but you have to make sure to get a "Chrysler" code reader (most OBD-I readers come with adapters for various plugs, and you just tell them what you're working on.)
CEL - Check Engine Lamp
MIL - Malfunction Indicator Lamp
OBD - OnBoard Diagnostics
MY - Model Year
SAE - Society of Automotive Engineers
DTC - Diagnostic Trouble Code
Matthew Currie said:Haynes lists 76 as "fuel pump resistor bypass relay circuit," or words to that effect. Of course you'd presumably have to have a fuel pump bypass resistor and relay for that code to be correct. There's no such code in the 95 FSM list, for example, as one would expect since there's no resistor. I don't know why such a code would appear on a 96. I'd suggest getting it read by an OBDII reader for confirmation.