 |
yankee9642
Cruiser Newbie
Posted: Feb 15, 2008, 3:22 PM
Post #1 of 10
(300 views)
Shortcut
|
|
PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
Hey guys, I've never posted here before, hello to you. I have a 2002 Pt cruiser with a check engine light, code says 703 which apparently is some brake circuit failure? I cannot find any information on any website pertaining tot his at all, what it is or how to fix it. Is this a serious problem? The car runs and drives fine- Can anyone please help me out? Thank you in advance-
-Damon
----------
|
|
Posts: 4 | From: N/A
| Registered: Feb 18, 2005, 10:30 PM
|
|
| |
|
rsobhian
Cruiser Expert
Posted: Feb 15, 2008, 5:51 PM
Post #2 of 10
(290 views)
Shortcut
|
|
Re: [yankee9642] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
P0703 = Brake Switch Sense Circuit
Basically, the PCM needs to receive a "high" signal from the brake lamp switch when you drive the car, and a "low" signal when you apply the brakes. This error means this signal is not detected.
The diagnostic procedures mostly center around testing the brake lamp switch itself and the ground (low side) wire, and the signal wire from the brake lamp to the PCM.
If all of that checks out, then you are looking at the worst case scenario, which is a faulty PCM - but don't panic just yet. Odds are it's the simple stuff.
Rather than getting into the details of all the testing of the wires and the switch, could you do a quick test and have someone operate the brake pedal and see if your brake lights are operating properly?
We'll take it from there.
----------
2001 silver Limited-Touring (leather/suede, 4W disk, traction, heated mirrors & all :-)
Mods: Tokico HP all around / Energy Suspension Master Kit / K&N drop-in / R1 Concepts drilled & slotte disks all around / Enkei RPF1 16x7 wheels & Conti Extreme Contact rubber / Prestige APS620 remote starter
(This post was edited by rsobhian on Feb 15, 2008, 6:57 PM)
|
|
Posts: 425 | From: MA
| Registered: Aug 2, 2007, 7:47 PM
|
|
| |
|
yankee9642
Cruiser Newbie
Posted: Feb 15, 2008, 6:35 PM
Post #3 of 10
(285 views)
Shortcut
|
|
Re: [rsobhian] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
I have tested the brake lights and they are all working fine. im not too familiar with these cars, but am trying to learn a bit ( it is my girlfriend's car) what is the PCM? Thanks for the quick reply i really appreciate it. let me know if you have any more information-
Thanks
Damon
----------
|
|
Posts: 4 | From: N/A
| Registered: Feb 18, 2005, 10:30 PM
|
|
| |
|
rsobhian
Cruiser Expert
Posted: Feb 15, 2008, 6:41 PM
Post #4 of 10
(284 views)
Shortcut
|
|
Re: [yankee9642] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
PCM = Powertrain Control Module (computer that controls the Engine)
PTs also had a Transmission Control Module (TCM) in '01 and part of '02 and then they built the TCM right in the PCM.
There is also a BCM (body CM) which controls alarm, lights...
Do you have a multimeter and do you feel comfortable unplugging things and testing connections?
----------
2001 silver Limited-Touring (leather/suede, 4W disk, traction, heated mirrors & all :-)
Mods: Tokico HP all around / Energy Suspension Master Kit / K&N drop-in / R1 Concepts drilled & slotte disks all around / Enkei RPF1 16x7 wheels & Conti Extreme Contact rubber / Prestige APS620 remote starter
(This post was edited by rsobhian on Feb 15, 2008, 6:58 PM)
|
|
Posts: 425 | From: MA
| Registered: Aug 2, 2007, 7:47 PM
|
|
| |
|
yankee9642
Cruiser Newbie
Posted: Feb 15, 2008, 7:01 PM
Post #5 of 10
(279 views)
Shortcut
|
|
Re: [rsobhian] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
I can check the battery voltage, but that's about it with the volt meter i have. how much does a new pcm cost and is it an easy replace? - thanks again for response-
Damon
----------
|
|
Posts: 4 | From: N/A
| Registered: Feb 18, 2005, 10:30 PM
|
|
| |
|
rsobhian
Cruiser Expert
Posted: Feb 15, 2008, 7:22 PM
Post #6 of 10
(277 views)
Shortcut
|
|
Re: [yankee9642] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
NP and you're welcome.
First, I have to say this in BOLD: I am not saying you need a PCM!
I just said that is your worst case scenario. I'm not sure how much they go for but they're probably around $1000 so you want to make sure you eliminate all other causes before replacing the PCM.
I'm not sure if you want to do this work yourself or have it done. I am just going to quickly list the diagnostic steps in the factory manual without getting into too much detail. Let me know if you want to do this yourself and if you need more info. - disconnect the brake lamp switch (under the dash mounted to the brake pedal)
- measure resistance between ground and the brake lamp switch ground circuit (the ground circuit may be bad)
- if not, disconnect the wiring harness from the PCM and check the resistance of the signal wire between the switch and the PCM (the connection may be bad)
- if not, check the functioning of the switch itself by operating the brake pedal and testing the resistance between the switch terminals (the switch may be bad)
- if not, with the PCM harness disconnected check the resistance of the PCM signal wire and ground to make sure it's not shorted out (resistance > 100 Kohms)
- if all of that checks out, then it says to replace the PCM.
----------
2001 silver Limited-Touring (leather/suede, 4W disk, traction, heated mirrors & all :-)
Mods: Tokico HP all around / Energy Suspension Master Kit / K&N drop-in / R1 Concepts drilled & slotte disks all around / Enkei RPF1 16x7 wheels & Conti Extreme Contact rubber / Prestige APS620 remote starter
|
|
Posts: 425 | From: MA
| Registered: Aug 2, 2007, 7:47 PM
|
|
| |
|
yankee9642
Cruiser Newbie
Posted: Feb 15, 2008, 7:54 PM
Post #7 of 10
(275 views)
Shortcut
|
|
Re: [rsobhian] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
ha, well i was just wondering how much the worst case scenario would cost lol. so i can work my way back from there. i dont trust myself with all the electrical stuff, as i dont know much about it. (im used to back wheel drive ford) but if there are any simple things i can do that u can think of let me know. like just checking a ground if it's loose or whatever. again im not good with the location of anything on this car so the best you can describe it would be great. hopefully it's just an easy fix so i dont have to take it in- thanks again
Damon
----------
|
|
Posts: 4 | From: N/A
| Registered: Feb 18, 2005, 10:30 PM
|
|
| |
|
silvereagle
Cruiser Addict
Posted: Feb 16, 2008, 5:28 AM
Post #8 of 10
(262 views)
Shortcut
|
|
Re: [yankee9642] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
If you want it simple try checking the brake fluid. ,Maybe bleed your brakes ,It could be just an air bubble in the lines. Let's hope so anyway. Other wise I'd take it to a dealer or someplace that can scan the system for you.
----------
big jim
(This post was edited by silvereagle on Feb 16, 2008, 5:29 AM)
|
|
Posts: 957 | From: New Castle ,Del, USA
| Registered: Aug 6, 2002, 12:00 AM
|
|
| |
|
sent1
Cruiser Expert
Posted: Feb 17, 2008, 6:48 AM
Post #9 of 10
(220 views)
Shortcut
|
|
Re: [silvereagle] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
I thought it was the "Brake" light that stayed on when the brake fluid was low. Add fluid and the light goes out.
With the way these systems are built though, I guess anything could happen. 
----------
DC1 #1610--5-speed. Its got some stuff.
'03 Inferno Red--Its getting some stuff too!
|
|
Posts: 424 | From: Salem, Oregon
| Registered: Apr 14, 2007, 8:56 AM
|
|
| |
|
silvereagle
Cruiser Addict
Posted: Feb 17, 2008, 8:37 AM
Post #10 of 10
(215 views)
Shortcut
|
|
Re: [sent1] PLEASE HELP CODE 703, can't figure out
|
Can't Post
|
|
It's all brake related. One has to do with the other
----------
big jim
|
|
Posts: 957 | From: New Castle ,Del, USA
| Registered: Aug 6, 2002, 12:00 AM
|
|
| |
|
|
Best Sellers |
 |
|
MAIN
SEARCH
WHO'S
LOG 
