check engine codes, help please

[bergs]

My 1996 bronco throws the following codes:

p0135

p0136

p0141

p0155

p0174

I know that they are for the 02 sensors and a lean condition. Whats your experience on tracking down these codes and keeping them from coming back.

 

[BroncoJoe19]

When it comes to codes... Miesk5 is the master.

Here is the thread that pertained to my O2 sensor experience with my '98 windstar.

http://broncozone.com/forums/index.php?s=&...ost&p=76967

 

[BroncoJoe19]

Here is a thread similar to your's

http://www.obd-codes.com/forums/viewtopic.php?f=1&t=2667

IF you would like more specific help, please post what the English version is for each of the numbered codes.

 

[miesk5]

yo!

thnx Joe!

Bergs, LOOK HERE

Before replacing O2 sensors, ck for an exhaust leak; Vacuum Leaks; intake leak after MAF sensor

 

[bergs]

thanks guys for your speedy replies. Theres a bunch of boogered up wiring on this truck. it had some kind of air horns mounted underneath it, whacky foglight(piaa) wiring under the hood, and some stereo wiring. I havent had a chance to even look at the truck too much. but i think its some of the wiring that previous owners did. I just got the truck. Which fuses should I check first. I noticed that there was a yellow wire coming out of the fuse box that is on the drivers side inner fender fuse box. the wire is cut and just hanging there. I didnt open it, but i figure its more of the old owners horrific wiring. i know the muffler is rusted out, i'll check the exhaust up by the cats and sensors for leaks too. I have a feeling that its butchered wiring, or deteriorated wiring, or a fuse.

 

[miesk5]

yo, yw

Yellow Wire... be wary of that one; I don't have good www connectivity here right now, but your Air Bag may be involved.

Wiring ia a mess. Suggest buying a FORD EVTM/PCED Service Manual CD on e bay to go thru the wiring and prob vacuum lines, etc. No one fuse for the sensors; just look at the sensors' connectors, & wires for corrosion or cuts..etc.

More on O2 sensors for you Berg;

Regardless of how the engine is mounted in the vehicle, conventional or transverse, the HO2S naming convention stays the same in relationship to engine banks 1 and 2. Bank 1 will always be the bank containing the #1 cylinder. See Fig. 1 in TSB 01-9-7

DRIVEABILITY - HO2S (HEATED OXYGEN SENSOR), CATALYST, AND FUEL SYSTEM MONITORS - SERVICE TIPS - OBD II VEHICLES ONLY - 96 Bronco, TSB 01-9-7

Source: by Ford via v8sho.com

Testing, Bronco & Ford - There may be three wires on the O2 sensor; two gray wires and one black. The black should read ground. One gray wire should read 12V with the ignition on, and the other gray wire is the one we are after. Probe this wire with the engine warm, and running with a voltmeter

 

[bergs]

i was cleaning up the wiring and noticed that there are a bunch of old connectors for old accesories going to the starter solenoid. the post that they go to has been extended with a bolt/nut combo to allow several round type connectors to fit on it. I cant get the bolt off to allow me to remove the connectors. also the stud that i am talking about wobbles and is loose. could this be the source of a bad ground causing the p0135, etc.? i think i may put in a new solenoid, your thoughts?

also i found a leak in the intake piping, the hose clamps on the throttle body hoses were totally loose. i tightened them up. so far no more lean condition code has come back.

 

[bergs]

i cleaned up all the wiring, and cant find any vacume leaks underhood. there is one in the dash board, the A/C only blows out of the defroster vents. I can hear the vacume hiss in there. could that be a reason? I think that there must be a problem with the wiring. Where is the PCM? i checked the wires on the sensors themselves and they look ok to me. at this point i wish i could just replace the H02S's and be done with it, but i think its some wiring issue. at this point its only throwing P0135, P0141, and P0155.

 

[BroncoJoe19]

i cleaned up all the wiring, and cant find any vacume leaks underhood. there is one in the dash board, the A/C only blows out of the defroster vents. I can hear the vacume hiss in there. could that be a reason? I think that there must be a problem with the wiring. Where is the PCM? i checked the wires on the sensors themselves and they look ok to me. at this point i wish i could just replace the H02S's and be done with it, but i think its some wiring issue. at this point its only throwing P0135, P0141, and P0155.

With that vacuum leak, it is letting air into the system which could allow one of the sensors to read a lean mixture.

A prerequisite to properly pulling codes is to check and correct vacuum leaks.

Hopefully it will be an easy one to get at.

joe

 

[BroncoJoe19]

: P0135 - HO2S Sensor : During testing the : * Short to VPWR in : - wiring. :

: Circuit Malfunction : HO2S Heaters are : harness or HO2S. : - Damaged HO2S :

: (HO2S-11) : checked for opens : * Water in harness : heater. :

: : /shorts and excessive : connector. : - Damaged PCM. :

: : current draw. The test : * Open VPWR circuit. :

: : fails when current : * Open GND circuit. :

: : draw exceeds a : * Low battery :

: : calibrated limit and : voltage. :

: : /or an open or short : * Corrosion or poor :

: : is detected. : mating terminals :

: : : and wiring :

: : : * Damaged HO2S :

: : : heater. :

: : : * Damaged PCM. :

.

Here is a list of grounds for a '92 - '96 bronc

I took a look in my Haynes manual.

They list 10 separate grounds... A-J.

A. Starter mounting bolt

B. Right front of Engine compartment near the battery

C. Lower left front of engine

D. Right front of engine compartment on upper radiator support.

E. Left front of engine compartment Upper radiator support

F. Bottom of cowl panel

G. Rear of left fender apron

H. Behind bottom of right cowl panel

I. Left rear corner of cargo area near rear lamp assembly

J. Under center rear of vehicle on rear cross member.

Take a look at the wiring diagram in your manual to see which of the listed grounds goes to the PCM, and check that one. Also Take a look at C that should be the ground for the O2 sensors.

 

[bergs]

: P0135 - HO2S Sensor : During testing the : * Short to VPWR in : - wiring. :: Circuit Malfunction : HO2S Heaters are : harness or HO2S. : - Damaged HO2S :

: (HO2S-11) : checked for opens : * Water in harness : heater. :

: : /shorts and excessive : connector. : - Damaged PCM. :

: : current draw. The test : * Open VPWR circuit. :

: : fails when current : * Open GND circuit. :

: : draw exceeds a : * Low battery :

: : calibrated limit and : voltage. :

: : /or an open or short : * Corrosion or poor :

: : is detected. : mating terminals :

: : : and wiring :

: : : * Damaged HO2S :

: : : heater. :

: : : * Damaged PCM. :

.

Here is a list of grounds for a '92 - '96 bronc

I took a look in my Haynes manual.

They list 10 separate grounds... A-J.

A. Starter mounting bolt

B. Right front of Engine compartment near the battery

C. Lower left front of engine

D. Right front of engine compartment on upper radiator support.

E. Left front of engine compartment Upper radiator support

F. Bottom of cowl panel

G. Rear of left fender apron

H. Behind bottom of right cowl panel

I. Left rear corner of cargo area near rear lamp assembly

J. Under center rear of vehicle on rear cross member.

Take a look at the wiring diagram in your manual to see which of the listed grounds goes to the PCM, and check that one. Also Take a look at C that should be the ground for the O2 sensors.

Thanks Joe! at least i have some direction now. I'm gonna pick up a haynes manual for sure. I dont have a wiring diagram, do you think you could look and see which ground is for the pcm. I'm sorry to be a pain, I really appreciate your help.

 

[michibronc]

Hey Bergs,

Try this link. It talks about a dirty MAF causing the lean code. There's also a lot of info on Miesk5's website at broncolinks.com. It's got an absolute wealth of info. I cruise it often!

good luck - I'm working through the same issues currently! Haven't had much time to play with it yet.

 

[bergs]

i'm looking for a ground at "the lower left front of engine" and i cant find one. all i see the the negative battery cable that attaches to the block on the lower passenger side. I cant tell where the o2 wires go. i can see that the passenger front sensor goes into a wiring loom that goes up to the starter solenoid (i think), but thats it? i have a digital volt meter but i dont know what setting to put it on, or how to use it at all. where do i stick the red and black prongs? any advise is much appreciated

 

[BroncoJoe19]

Looks like B G and E are important grounds.

Also it appears that the orientation of left and right is that Right is the passenger side.

I don't have my truck here to take a look at it, (mine is a '90 anyway)

If you have a good ground to the block, it doesn't matter.. left or right.

 

[miesk5]

yo,

awhile ago, I went thru my 1996 Ford Electrical & Vacuum Troubleshooting Manual (EVTM), Service, etc. Tech publication CD and saved this on Grounds:

10-2 Grounds

LH front of engine compartment, on upper radiator support (F7) G100

G101 RH front of engine compartment, front of fender apron (D1) - RH = Passenger side mine has 2 small black wirres near starter relay

G103 (battery to engine) Lower RH front of engine (C1)

Component

4WABS Pump Motor

Battery

Data Link Connector (DLC)

Mass Air Flow (MAF) Sensor

Powertrain Control Module (PCM), 5.0L

Powertrain Control Module (PCM), 5.8L

Right Front Park/Turn Lamp

Right Front Side Marker Lamp

Right Headlamp

G104 Rear of LH fender apron (A9)

G200 Behind bottom of RH cowl panel (F7)

G201 Behind bottom of LH cowl panel (E1)

G400 Rear Window Defroster 56-1

LH rear corner of cargo area, near rear lamp assembly (F8)

G401 Trailer/Camper Adapter 95-3

LH rear corner of cargo area, near rear lamp assembly (F9)

10-3 Grounds

Component

A/C Clutch Diode

A/C Clutch Field Coil

Fuel Pump Module SPLICED Rear lamps harness, near T/O to fuel pump module

Left Backup Lamp

Left License Lamp

Left Rear Park/Stop/Turn Lamp

Right Backup Lamp

Right License Lamp

Right Rear Park/Stop/Turn Lamp

Transmission Range (TR) Sensor, with 4R70W Transmission

Transmission Range (TR) Sensor, with E4OD Transmission

Lower RH front of engine (C1)

Grounds 10-5

Behind bottom of RH cowl panel (F7)

Component

Air Bag Diagnostic Monitor

Electronic Shift Control Module

Instrument Cluster

Programmable Speedometer/Odometer Module (PSOM)

Remote/Keyless Entry Module

Speed Control Servo/Amplifier Assembly

Grounds 10-6

Behind bottom of LH cowl panel (E1)

Component

Compass/Outside Temperature Module

Day/Night Mirror

Inside Cargo Lamp

Left Power Lumbar Compressor Motor

Outside Cargo/High Mount Stop Lamps

Right Power Lumbar Compressor Motor

Seat Belt Switch

G100 & G104 (tied together in diagram) Grounds 10-11

LH front of engine compartment, on upper radiator support (F7)

Grounds 10-11

Rear of LH fender apron (A9)

Grounds 10-11

Rear of LH fender apron (A9)

Component

4WABS Control Module

4WABS Data Link Connector

4WABS Relay #1

Instrument Cluster

Powertrain Control Module (PCM), 5.0L

Powertrain Control Module (PCM), 5.8L

Programmable Speedometer/Odometer Module (PSOM)

Trailer Relay Box

G100 LH front of engine compartment, on upper radiator support (F7)

Component

Fuel Pump Module

Inertia Fuel Shutoff

Misfire Sensor

Misfire Sensor Shield

Output Shaft Speed (OSS) Sensor

Powertrain Control Module (PCM), 5.0L

Grounds 10-6

Behind bottom of LH cowl panel (E1)

as you can see, some are repetitive because I haven't lined all these up yet. And the CD didn't show the battery ground yet... still need to look at it again when things slow down here.

I think I need a full session on the PC to coordinate all grounds to individual components, as well as linking them to every connector.

& on my 96, the RH Engine Ground also branches to RH firewall near heater box & down to frame

 

[bergs]

I'm going to clean up the grounds that i can find and see what that does. Can someone give me a quick run down of the procedure of testing the o2 sensors with the digital multi meter. i have the meter but i dont know where to probe or if the truck should be running or anything. if i could actually test the wiring i'd be in better shape. Thanks for all your replies so far. you guys have been a big help.

 

[miesk5]

I'm going to clean up the grounds that i can find and see what that does. Can someone give me a quick run down of the procedure of testing the o2 sensors with the digital multi meter. i have the meter but i dont know where to probe or if the truck should be running or anything. if i could actually test the wiring i'd be in better shape. Thanks for all your replies so far. you guys have been a big help.

bergs, take a look @ one of replies aboce on teesting the O2 sensors; see if thay have the 3 wire leads.

Testing, Bronco & Ford - There may be three wires on the O2 sensor; two gray wires and one black. The black should read ground. One gray wire should read 12V with the ignition on, and the other gray wire is the one we are after. Probe this wire with the engine warm, and running with a voltmeter

 

[bergs]

bergs, take a look @ one of replies aboce on teesting the O2 sensors; see if thay have the 3 wire leads.
Testing, Bronco & Ford - There may be three wires on the O2 sensor; two gray wires and one black. The black should read ground. One gray wire should read 12V with the ignition on, and the other gray wire is the one we are after. Probe this wire with the engine warm, and running with a voltmeter

 

[miesk5]

ok, i'll try this when i get home. I also noticed that in the wire loom that goes to the ignition coil there is a black wire that is sticking out and not connected to anything. could that be part of the problem?

I think that vacuum leak needs to be addressed 1st

then we can look at that wire; take a pic of it and post it here if you can berg

next;

btw, we have 3 O2 Sensors in our 96 5.0/5.8; One in each exh manifold and one before cat

Locations, 96 Bronco, F Series, Explorer, Expedition, etc. Source: by Ford it shows the 4th for CALIF SMOG

(Calif Emission freaked-out Broncos have 4 O2 sensors)

O2 Sensor Cleaning by oxygensensor4less.com