96 Bronco 5.0 O2 and ABS lights on TSB questions

[calvin0325]

Ok, I have a 96 Bronco 5.0 with the check engine and abs dash lights on. After having codes pulled by Autozone, I have faults for all 3 O2 sensors. I know there is a TSB out there for this problem, and I have read it and wanted to start there. Here is where it gets interesting, when I went out to inspect my harness I noticed something wierd. On the harness connector (round 8 pin between battery and starter solenoid) the one side of the body harness connector has 6 wires running into it yet on my harness running down to the engine, it only has 2 wires on that side of the connector. Is this right????? It doesn't sound right to me as that would leave 4 wires not going anywhere. I tried to look for a pin out of this connector but have yet to find it. Any help would be appreciated.

[miesk5]

yo CALVIN,
Can you pin-point this connector?

Item Part Number Description
1 11450 Starter Motor Relay Assembly
2 N803991-S36 Screw
3 14A396 Cap
4 381561-S36 Nut and Washer Assembly
5 14B060 Cable Assembly
6 � Starter Solenoid Heat Shield 5.0L/5.8L Only (Part of 11002)
7 382747-S36 Screw and Washer Assembly
8 N805403-S100 Nut and Washer Assembly
9 11N087 Cover � Starter Solenoid (Red)
10 56558-S Bolt
11 34943-S36 Star Washer
12 14301 To Engine Ground
13 12A690 Wire Assembly
14 11002 Starter Motor
15 � To Heated Oxygen Sensor for 5.0L/5.8L Under 8500, 5.8L over 8500 and 7.5L F-450
16 N621906-S36 Nut
17 N806925-S36MG Stud
18 12A581 Body Grounds
19 14301 Chassis Ground
20 For Continuation Refer to Fender Apron, Right, Gasoline Engines Illustration Shown Previously in this Section
21 To Heated Oxygen Sensor for 5.0L/5.8L Under 8500, 7.5L F-450 22 12A690 Wiring Assembly For 5.8L Bronco
23 N802777-S36 Bolt for 14301 Frame Ground
24 9S286 Existing Gas Vapor Tube
25 10655 Battery
26 33799-S2 Nut (Auto Transmission)
27 5A212 Exhaust Pipe


===



Item Part Number Description
1 � Place Locator in Hole Provided
2 8496 Radiator Support
3 � To RH Headlamp
4 � To RH Park
5 � Body Grounds (Part of 12A581)
6 � To Starter Motor Relay Battery Terminal
7 11450 Starter Motor Relay Assembly
8 � To Starter Motor Relay (Part of 12A581)
9 14305 To Starter Motor Relay
10 � To 14305
11 14305 Wiring Assembly
12 9F472 Heated Oxygen Sensor Assembly � All Gasoline Engines Except 5.8L over 8500 and 7.5L
13 14B060 Wiring Assembly
14 12A581 Wiring Assembly
15 � To RH Air Bag Sensor
16 10372 Battery Tray
17 � To RH Park and Turn Lamp
18 � To Horns
19 14301 Chassis Ground
20 N621906-S36 Nut
21 N806925-S36MG Stud
22 N806327-S190 Screw
23 14B004 Sensor and Bracket Assembly
24 � Front End Sheet Metal Seal (Part of 5005)
25 � For Continuation See Main View
26 12A581 Wire Assembly
27 � Cap
==

Connector Location in Full Body Diagram in a 96 5.0 & 5.8, Page 2
Source: by Ford via Chilton http://content.chiltonsonline.com/co...ord_172141.pdf

Connector Pin-Out Diagram in a 96 w/Nomenclature
Source: by HardMaple at Ford Bronco Zone Forums
http://broncozone.com/topic/15022-o2..._20__start__20

[calvin0325]

on the first picture....bottom left in view B it is connector 21. It says it is for the O2 sensors. That connector on mine only has 2 wires coming off of it on that side of the harness. On the body side of the harness it has 6 wires going into it, doesnt make sense to me. i can even send you a picture of it....Can you look at yours in that same location and see if that is right???? From one military member to another ...Thanks.

[Steve83]

Read this & upload your pics:
http://www.fullsizebronco.com/forums/th...-and-or-videos

Follow the wires from each oxygen sensor. Stay out of the zone.

[miesk5]

yo CALVIN, Same here; 6 wires and then 2
C1025 Lower RH rear of engine, near starter on heated oxygen sensor (HO2S) #11 (A2) Terminal: 04

#11 is near the engine on same side as #1 cylinder
C1025 Lower RH rear of engine, near starter on heated oxygen sensor (HO2S) #11 (A2) Terminal: 04

RED from Splice S151
Red/W into C101F side into 101 Male side to PCM

Heater Side
Gray/LB from PCM into C1025F side into 1025 Male Side
Gray/R into 1025 Male Side to 1025 Female side to Splice

Pics coming soon;

[miesk5]

C102 (Brake Pressure Switch), C103, C106, C109, C121 (4WABS HCU), C123 (Left Front Wheel ABS Sensor), C126 (AC High Pressure Cut-Out Switch), C135 (Oil Pressure Switch), C139, C149, C151 (Windshield Wiper Motor), C152 (Speed Control Servo/Amplifier), C153 & C154 (Integral Alternator/Regulator (IAR)), C162 (AC Clutch Cycling Pressure Switch), C163 (AC Clutch Field Coil) , C168 (Blower Motor), C169 (Blower Motor Resistor), C170 (Brake Fluid Level Switch), C173, C177 (Daytime Running Lamps (DRL) Jumper w/out DRL) or C177 (Daytime Running Lamps (DRL) Module w/ DRL), C202 (Engine Bay at Firewall to Dash Harness), C205 (in Engine Bay at Firewall to Dash Harness), C1005 (Low Pitch Horn), C1006 (High Pitch Horn), C1030 (WS Washer Fluid Pump Motor), C1031 (Left Front Park/Turn Lamp), C1032 (Right Front Park/Turn Lamp), C1033 (Left Headlamp), C1034 (Right Headlamp), C1035 (to Engine Compartment Lamp), C1052 & C1053 (Right Front Side Marker Lamps), C1054 & C1055 (Left Front Side Marker Lamps), AC Clutch Diode, Engine Compartment Fuse Box ( Trailer Relay Box Inside), Right & Left Primary Crash Sensors, & Grounds G100, G101, G103, G104 Connector Location in Engine Bay Diagram in a 96
Source: by Mikey350

[miesk5]

yo, OK, I got it figured out; in 96 EVTM, C139 F& M is part of Charging System for Instr Cluster "Charge Indicator" (LG/R), ckt 904, etc.; probably other ckts are in there as well; but as you can see from HEGO wiring, it is not shown in cht

[calvin0325]

Yeah it didnt make sense to me at all...now looking at the EVTM, I am good....will just have to go out to the truck and take the fluke and start doing pinpoint test till iI find my problem with the check engine light, then move on to the ABS light.

[miesk5]

yo CALVIN,
ok, Still trying to get out to snap pics; so I'll skip the pics now; had to really pull harness wrap to view wires; but I ended up with long vids instead of pics..lol; am ham handed now and trying to pull wrap back, hold LED light and snap i phone pic... so maybe I'll have a CEL when I start it up? lol

[calvin0325]

lol...I checked my harness and all looks good on that side. I am now going to move over and start testing on the O2 side and check my readings there. Considering the EGR system was junk when I got it I expect the O2's to be toast. As long as the wiring is good and I am getting the readings from the computer like I should I will be happy to put new sensors in it and fix the problem.

[Steve83]

EGR doesn't have much effect on HEGOs, and new HEGOs won't fix any problems.

[miesk5]

yo CALVIN,
Have codes pulled by Autozone again

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.
Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to:
KOEO
&
KOER

They may say that KOER is not required, but ask them to do it
The KOER Test provides hard DTCs only


Perform the Visual Check and Vehicle Preparation procedures as outlined in the Powertrain Control/Emissions Diagnosis Manual OBDI or OBDII.

Inspect the following:

Air cleaner and inlet ducting.
All engine vacuum hoses for damage: leaks, cracks, blockage, proper routing, etc.
PCM system wiring harnesses for proper connections, bent or broken pins, corrosion, loose wires, proper routing, etc.
PCM, sensors and actuator for physical damage.
Engine coolant for proper level.
Transmission fluid for proper level and condition.
Any non-factory installed items wired into the transmission or PCM harnesses.
NOTE: Perform all necessary service before continuing with Quick Tests