93 bronco xlt 5.0 e4od. I have a vibration. It's like driving on rumble strips but worse. Spent a lot of time trying to figure out the problem. I tested the last thing I could think of yesterday. As I am cruising along and have the vibration occuring, I hit my hazard light button. It stops the vibration completely. The rpms raise a bit at the same time the vibration stops. What shuts off when I hit the button?
hazard light switch stops vibration
- Thread starter numsleven
- Start date
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yo,
Do both brake & rear turn signal bulbs operate?
Brake On/Off (BOO) Switch: The brake on/off switch tells the powertrain control module when the brakes are applied. The switch is closed when the brakes are applied and open when they are released. The PCM uses this signal to disengage torque converter clutch when brake is applied. Failed on or not connected — Torque converter clutch will not engage at less than 1/3 throttle. Failed off — Torque converter clutch will not disengage when brake is applied. DTC: 536, P1703
"...I was living with the torque converter unlocking with the R/H turn signal. And low and behold after I changed the L/H brake/turn signal bulb the torque converter stopped unlocking with the R/H turn signal. Don't ask me but it did fix it..."
Source: by Mike G & Miesk5 at Ford Bronco Zone Forums
http://broncozone.com/topic/19380-torque-converter-unlocking-by-right-turn-signal/
Multi-Function Switch (MFS), Hazard & Brake Light MAY Disengage E4OD Torque Converter Lock-up Discussion in 92-96
Source: by members at http://www.nloc.net/vbforum/gen-1-lightnings/171558-hazard-lights-disengage-torque-converter-lockup-how.html
They discuss PCM Pin 2
So,this Park, Brake & Turn & High Mount, HeadLight, Side Marker, Hazard Wiring Diagram in 92-95 Bronco & F Series
Source: by Steve83
Pin 2 is marked "to Brake Switch (E4OD)" and circuit
So, in at least 89-95 PCM Pin 2 is marked BOO;
in 96 PCM Pin 92 is marked Stoplamp (Brake On/Off) Switch to Stoplamps
Do both brake & rear turn signal bulbs operate?
Brake On/Off (BOO) Switch: The brake on/off switch tells the powertrain control module when the brakes are applied. The switch is closed when the brakes are applied and open when they are released. The PCM uses this signal to disengage torque converter clutch when brake is applied. Failed on or not connected — Torque converter clutch will not engage at less than 1/3 throttle. Failed off — Torque converter clutch will not disengage when brake is applied. DTC: 536, P1703
"...I was living with the torque converter unlocking with the R/H turn signal. And low and behold after I changed the L/H brake/turn signal bulb the torque converter stopped unlocking with the R/H turn signal. Don't ask me but it did fix it..."
Source: by Mike G & Miesk5 at Ford Bronco Zone Forums
http://broncozone.com/topic/19380-torque-converter-unlocking-by-right-turn-signal/
Multi-Function Switch (MFS), Hazard & Brake Light MAY Disengage E4OD Torque Converter Lock-up Discussion in 92-96
Source: by members at http://www.nloc.net/vbforum/gen-1-lightnings/171558-hazard-lights-disengage-torque-converter-lockup-how.html
They discuss PCM Pin 2
So,this Park, Brake & Turn & High Mount, HeadLight, Side Marker, Hazard Wiring Diagram in 92-95 Bronco & F Series
Source: by Steve83
Pin 2 is marked "to Brake Switch (E4OD)" and circuit
So, in at least 89-95 PCM Pin 2 is marked BOO;
in 96 PCM Pin 92 is marked Stoplamp (Brake On/Off) Switch to Stoplamps
Last edited by a moderator:
I tested the brake lights, turn signals, hazard lights and everything connected to those. I didn't notice any problems untill my ride to work tonite. As I hit my brakes, the brake lights tended to flicker on and off occasionally. Some of time they worked properly. The rest of time not so well. The turn signal thing mentioned, how using the one would interfere with the switch, didn't happen.
yo,
ok, repair brake light ckt; ck bulbs for damage or corrosion - same for sockets
my 96's stop/turn/tail lights wires were almost cut in half on passenger side against 1/4 panel (inner); wires pinched @ high mount brake light & @ driver's left hand seat belt anchor bolt @ base of B Pillar.
Brake On-Off Switch, Brake Light & High Mounted Brake Lamp, Back-UP Lamp, License Lamp, Turn Signal, Daytime Running Lights Module, HeadLight, Hazard, Trailer Marker Relay, etc. Wiring Diagram in 92-96 Bronco & F 150
Source: by seijirou at http://www.supermotors.net/clubs/fullsizebronco/registry/media/588539
ok, repair brake light ckt; ck bulbs for damage or corrosion - same for sockets
my 96's stop/turn/tail lights wires were almost cut in half on passenger side against 1/4 panel (inner); wires pinched @ high mount brake light & @ driver's left hand seat belt anchor bolt @ base of B Pillar.
Brake On-Off Switch, Brake Light & High Mounted Brake Lamp, Back-UP Lamp, License Lamp, Turn Signal, Daytime Running Lights Module, HeadLight, Hazard, Trailer Marker Relay, etc. Wiring Diagram in 92-96 Bronco & F 150
Source: by seijirou at http://www.supermotors.net/clubs/fullsizebronco/registry/media/588539
Well I went out and bought a new brake switch as the diagram of the location of the switch was clear. Found exactly where it was and installed the new one. Well install seems a bit much for the simplicity of putting a new one in. Pin out, pull switch. Put switch in, push pin back. I was having trouble with my wiper switch not wanting to work right so I went ahead and bought a new one and put that in too. Too early to tell if the brake switch helped since I haven't time to go running about but ill find out on my drive to work tonite and then update the news. What's the very least that came out of this u ask? New parts installed, waste of 5 mins, I see it as every new part gets me that much closer to having the old bronco run like new. Which all in all that is the goal. The goal sucks, part here or there over large amounts of time. We need a national free salvage day where we can all go out and pick the world clean of bronco parts. Bronco holiday....could anyone imagaine that. Side note my steering wheel sucks anymore. It ozzzs black goo. I can easily buy a new one or a cover but is there any remedy for this tar like substance? Sorry about the jibborious, on the verge of nite time which means few beers in, sleep , then wake up, back to work.
The brake switch didn't change anything as I figured. So far I know that th hazard light switch stops the vibration. I found out something new that doesn't allow it to happen. Driving up an incline or driving down hill at normal road speeds. The only time the vibration happens is driving on level roads. When going up hill, where the vibrating would normally start if I were driving on level ground, the rpms and gears seem to shutter a little bit but work normal. It surprised me when the vibrating didn't happen. This is all leading me to believe the computer may be malfunctioning and my other thought about the truck had been in a flood like the one we recently had here a couple months ago to be true.
yo,
What happens when brake lights flicker while driving up hill and when on level road?
If flickering; you need to go thru the electrical brake/turn Circuits; Ford suggests a "wiggle test" on connectors and harnesses
Hazard, Turn, High & Low Headlight Dimmer, Flash-to-Pass, Multi-function Switch (MFS) & Brake Light Testing & Wiring Diagram in 92-96; Hazard, Turn, High & Low Headlight Dimmer, Flash-to-Pass, Multi-function Switch (MFS) & Brake Light Testing & Wiring Diagram in 92-96; "...the MFS testing is done with connectors disconnected; it's strictly an internal test of the MFS;
..." Miesk5 NOTE; Brake Light & Turn, High & Low Headlight Dimmer, Flash-to-Pass & Hazard CKTs are a Feed-Through Circuit in Multi-function Switch (MFS). The turn signal system is deactivated when the hazard flasher system is on. Turn signal lever motion does not affect the hazard flasher system. The hazard flasher system operates independently from the ignition switch (11572). All turn signal lamps can be made to flash in unison by depressing and releasing the hazard actuator located on the top part of the steering column. The switch is identified by a double triangle symbol. The actuator will move out or away from the steering column tube (3514) to the ON position. The hazard flasher system is turned off by first pushing in the actuator and then releasing the actuator. The actuator should remain in or toward the steering column in the OFF position..."
Source: by Steve83 (Steve, That dirty old truck) at http://www.supermotors.net/registry/media/225114_1
Also,
torque converter test;
This test verifies that the torque converter clutch control system and the torque converter are operating correctly.
1. Carry out Quick Test with scan tool. For additional information, refer to the Powertrain Control/Emissions Diagnosis manual (PCED). Check for DTCs.
2. Connect a tachometer to the engine.
3. Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in (D) position.
4. After normal operating temperature is reached, maintain a constant vehicle speed of about 80 km/h (50 mph) and tap brake pedal with the left foot.
5. Engine rpm should increase when brake pedal is tapped, and decrease about five seconds after pedal is released. If this does not occur, see torque converter operation concerns. 6. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, move the transmission range selector lever to manual 1 position. If the vehicle stalls, see torque converter operation concerns.
7. If the vehicle exhibits a vibration during the road test complete the Road Test Evaluation Form. This form will aid the technician in determining the source of the vibration.
If the shudder occurs a) during the 3-4 or 4-3 shift at HEAVY throttle,
or B) at 40mph in 2, OD OFF,
and OD, or c) at the same RPM in every gear,
or d) coasting, cruising, or in R, or e) during extended light braking, then it is NOT TC clutch shudder.
The following is a list of common vehicle concerns that have been misdiagnosed as torque converter clutch shudder. For diagnosis of the following items, refer to the appropriate sections of the workshop manual and the Powertrain Control/Emissions Diagnosis manual (PCED).
> Spark plugs - check for cracks, high resistance or broken insulators.
> Plug wires.
> Fuel injector - filter may be plugged.
> Fuel contamination - engine runs poorly.
> EGR valve - valve may let in too much exhaust gas and cause engine to run lean.
> Vacuum leak - engine will not get correct air/fuel mixture.
> MAP/MAF sensor - improper air/fuel mixture.
> HO2S sensor - too rich/lean air/fuel mixture.
> Fuel pressure - may be too low.
> Engine mounts -loose/damaged mounts can cause vibration concerns.
> Axle joints - check for vibration.
Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19
http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded
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
What happens when brake lights flicker while driving up hill and when on level road?
If flickering; you need to go thru the electrical brake/turn Circuits; Ford suggests a "wiggle test" on connectors and harnesses
Hazard, Turn, High & Low Headlight Dimmer, Flash-to-Pass, Multi-function Switch (MFS) & Brake Light Testing & Wiring Diagram in 92-96; Hazard, Turn, High & Low Headlight Dimmer, Flash-to-Pass, Multi-function Switch (MFS) & Brake Light Testing & Wiring Diagram in 92-96; "...the MFS testing is done with connectors disconnected; it's strictly an internal test of the MFS;
..." Miesk5 NOTE; Brake Light & Turn, High & Low Headlight Dimmer, Flash-to-Pass & Hazard CKTs are a Feed-Through Circuit in Multi-function Switch (MFS). The turn signal system is deactivated when the hazard flasher system is on. Turn signal lever motion does not affect the hazard flasher system. The hazard flasher system operates independently from the ignition switch (11572). All turn signal lamps can be made to flash in unison by depressing and releasing the hazard actuator located on the top part of the steering column. The switch is identified by a double triangle symbol. The actuator will move out or away from the steering column tube (3514) to the ON position. The hazard flasher system is turned off by first pushing in the actuator and then releasing the actuator. The actuator should remain in or toward the steering column in the OFF position..."
Source: by Steve83 (Steve, That dirty old truck) at http://www.supermotors.net/registry/media/225114_1
Also,
torque converter test;
This test verifies that the torque converter clutch control system and the torque converter are operating correctly.
1. Carry out Quick Test with scan tool. For additional information, refer to the Powertrain Control/Emissions Diagnosis manual (PCED). Check for DTCs.
2. Connect a tachometer to the engine.
3. Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in (D) position.
4. After normal operating temperature is reached, maintain a constant vehicle speed of about 80 km/h (50 mph) and tap brake pedal with the left foot.
5. Engine rpm should increase when brake pedal is tapped, and decrease about five seconds after pedal is released. If this does not occur, see torque converter operation concerns. 6. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, move the transmission range selector lever to manual 1 position. If the vehicle stalls, see torque converter operation concerns.
7. If the vehicle exhibits a vibration during the road test complete the Road Test Evaluation Form. This form will aid the technician in determining the source of the vibration.
If the shudder occurs a) during the 3-4 or 4-3 shift at HEAVY throttle,
or B) at 40mph in 2, OD OFF,
and OD, or c) at the same RPM in every gear,
or d) coasting, cruising, or in R, or e) during extended light braking, then it is NOT TC clutch shudder.
The following is a list of common vehicle concerns that have been misdiagnosed as torque converter clutch shudder. For diagnosis of the following items, refer to the appropriate sections of the workshop manual and the Powertrain Control/Emissions Diagnosis manual (PCED).
> Spark plugs - check for cracks, high resistance or broken insulators.
> Plug wires.
> Fuel injector - filter may be plugged.
> Fuel contamination - engine runs poorly.
> EGR valve - valve may let in too much exhaust gas and cause engine to run lean.
> Vacuum leak - engine will not get correct air/fuel mixture.
> MAP/MAF sensor - improper air/fuel mixture.
> HO2S sensor - too rich/lean air/fuel mixture.
> Fuel pressure - may be too low.
> Engine mounts -loose/damaged mounts can cause vibration concerns.
> Axle joints - check for vibration.
Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19
http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded
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
I took care of the flickering brake light. Changing out the switch fixed it. I also changed out the MFS with a new one which I did mostly for the wiper delays to work properly. I have found a vaccum leak but its just one connected to the ac system. Everything I have installed so far is in the list below with the prices next to them.
Pvc valve 8
Exhaust muffler 40
MAP sensor 40
Air filter 10
Spark plugs 24
Tailgate cables 20
Front/rear shocks 120
Driver side door striker 10
Front speakers, kicker 80
Wheel cylinder rear passenger 10
Rear drum hardware 10
Rear carpet Free
Exhuast hanger 7
Lug nuts 52
Soft top 300/weather seal 12
Tail light covers free
Trans filter Gasket+new fluid 38
Mile marker hubs 89
Tailgate strikers bushings 6
Comb. switch wipers/4way 58
Stop light switch 8
Passenger side door striker bushing
I will get some new pictures up when I have the time. By the way this truck is unreal when it comes to rust on broncos. I have nearly none on it except for the bottom of the tailgate. As far as the vibration problem is going, it is an electrical problem. That is obvious. It will take me some time to go through testing all the wires and sensors.
Pvc valve 8
Exhaust muffler 40
MAP sensor 40
Air filter 10
Spark plugs 24
Tailgate cables 20
Front/rear shocks 120
Driver side door striker 10
Front speakers, kicker 80
Wheel cylinder rear passenger 10
Rear drum hardware 10
Rear carpet Free
Exhuast hanger 7
Lug nuts 52
Soft top 300/weather seal 12
Tail light covers free
Trans filter Gasket+new fluid 38
Mile marker hubs 89
Tailgate strikers bushings 6
Comb. switch wipers/4way 58
Stop light switch 8
Passenger side door striker bushing
I will get some new pictures up when I have the time. By the way this truck is unreal when it comes to rust on broncos. I have nearly none on it except for the bottom of the tailgate. As far as the vibration problem is going, it is an electrical problem. That is obvious. It will take me some time to go through testing all the wires and sensors.
Last edited by a moderator:
yo,
ok, do the self test for codes first..
btw, Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.
http://broncograveyard.com
ok, do the self test for codes first..
btw, Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.
http://broncograveyard.com
I'm picking up a code reader this weekend. I have no check engine lights on but I figured it would be good to look anyway. Most of the parts I bought was before I knew of the graveyard and I knew there was a code for a discount but I had forgotten it. I kept putting only the bz part in thinking that was all to it. Junkyard after work. Gonna be like a shopping spree for me.
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