PMIII Error Code..what's it mean?

[The Burning Rom]

Alright, I sat in the TGP last night and counted the flashing ANTI-LOCK light, and the code came out to be A042. And according to the chart Chris has on the site, it means that the Low Brake Pressure circuit open. Is this being caused by a bad accumulator? Or a bad Pressure switch? Or something else?   :?  I'm hoping it's not the whole PMIII unit..because I can't afford to rebuild that right now.  :oops:

[Chris A]

Counted?

THe only way I know to get codes is with a scanner. I've never seen another way?

If you are counting it because it flashes with the key on, thats not a code, it flashes when there is an error that isn't fatal (abs still operative) its solid if its a fatal error (abs disabled).

Code A042 is just for indicating a problem with the RED brake warning lamp in the dash. (this system monitors EVERYTHING!)

The red brake light operates from several sources by the source switching from ground to open. Either the parking brake, low fluid level or low accumulator pressure can turn on the light (this is actually a solid state control, the lamp driver module). Normally the pressure switch is grounded above 1800psi accumulator pressure. If it drops below this pressure, the switch will open the circuit turning on the RED light. The abs module is also connected to this circuit. When the lamp driver module loses the ground, it applies a voltage to the circuit. If the abs  module does not see the lamp driver module switch, it sets a code a042.

Chris

[The Burning Rom]

Counted?

THe only way I know to get codes is with a scanner. I've never seen another way?

If you are counting it because it flashes with the key on, thats not a code, it flashes when there is an error that isn't fatal (abs still operative) its solid if its a fatal error (abs disabled).

Code A042 is just for indicating a problem with the RED brake warning lamp in the dash. (this system monitors EVERYTHING!)

The red brake light operates from several sources by the source switching from ground to open. Either the parking brake, low fluid level or low accumulator pressure can turn on the light (this is actually a solid state control, the lamp driver module). Normally the pressure switch is grounded above 1800psi accumulator pressure. If it drops below this pressure, the switch will open the circuit turning on the RED light. The abs module is also connected to this circuit. When the lamp driver module loses the ground, it applies a voltage to the circuit. If the abs  module does not see the lamp driver module switch, it sets a code a042.

Chris

Actually there is another way to get the codes besides a scanner..there has to be by law. This is something I learned from my dad. Back in the late 80s and early 90s Chrysler tried going to just scanners to get the error codes, but the government made them have a way for the common man (and small car shops) to get the codes...all car companies had to have a way to get an error code without a scanner. And that way is counting how many times the light flashes(be it abs, brake, check gauges, etc) when the key is in the ON position. To check engine error codes, you have to jump two pins on the diagnostic connector, but I'm not sure what two pins they are. Anyway..I counted, and it flashed 42 times..which means it's code is 42. We just fixed the O2 sensor problem in my moms car with this method. The light flashes indicated an O2 sensor problem, and that's what it was. Cars may not be like this anymore as laws may have changed, but in 1990 this law was still in place.

And by your explanation of the code, it must be the accumulator, because the unit is really sucking in the functioning department. You can't even step on the pedal a little without the pump running.

[Chris A]

The law may be true for engine codes as just about every car has a way to retrieve trouble codes without a scanner up until OBD II. However, I've seen no mention of that for abs codes on this car. There are some cars that can do it this way (in some cases its the only way to get codes) but I still think that if you just counted the flashes you are not getting the right code. I have several abs manuals and I would have figured it would have been mentioned in at least one of them if not all.

Besides this code has nothing to do with the accumulator itself this is just for the RED brake light circuit to the lamp driver module. CODE A062 is usually what guys will get with a bad accumulator. The motor will typically short cycle because there is less volume in the accumulator for brake fluid to displace (the nitrogen charged bladder is bad, so there is nothing for the brake fluid to pump up against and maintain pressure). The computer picks up on this short cycling and sets this code.

Chris