93 k2500 suburban obd1 code 53

[nutpants]

i have an error code of 53 on my 93 suburban.
checking the voltage at the battery while running is 14.4 volts
clearing the codes and not starting the truck at all still gives me a code 53..
is my pcm in need of replacement or i have i missed something.?

nutz

[unplugged]

Could be a low voltage condition since the ecm sets at less than 10vdc and greater than 17vdc. What is the overall condition of the burb and how old is the alternator? Have the battery load tested and the alternator checked. Take them into your local parts store for testing.


Code 53- System overcharging. This code will set if the ecm sees more than 17 volts, or less than 10 volts. Overcharge is mostly likely the cause of a faulty voltage regulator in the alternator. Have charging system checked before replacing alternator.

[nutpants]

the suburban is in good shape over all
i just bought it and there appears to have been some questionable work done on it.
i have checked wiring grounds and voltage drop on every connecting that should matter
i have checked the voltage at the battery and pcm and both are the same 12.5-13 off 14.4 running.

Mitchell and all data say this is a electronic transmission errorcode even though diagnoses is the charging system. strange that...

alternator checks out (just been replaced)
battery is old but in good shape i have tried 3 different batteries.

im still stumped.

nutz

[Jimmiee]

The problem with OBD I is there was no uniformity with codes and the same code changed from year to year and model to model. SAE <the society of automotive engineers> corrected this problem with strict OBD II rules.
A code 53 can mean
1. No distributor reference pulses. or
2. EGR Solenoid Circuit. or
3. High battery voltage 17 volts or higher. or
4. Passkey circuit.

So take your pick. You may not have a voltage problem at all.

[nutpants]

this is what mirchell and alldata have to say for error code 53

DTC 53 will set when the ignition is "ON" and PCM terminal "D1" or TCM terminal "A12" voltage is greater than 19.5 volts for 2 seconds.During the time the fault is present, the pressure control solenoid is turned "OFF," transmission shifts immediately to 2nd gear, and TCC operationis inhibited. The setting of additional codes may result.
TEST DESCRIPTION:Number(s) below refer to circled number(s) on the diagnostic chart.
1.Normal battery voltage is between 9-15 volts.
2.This test checks if the high voltage reading is due to the generator, CKT 440 or PCM/TCM, with engine operating, check voltage at the battery.If the voltage is greater than 15 volts, the PCM/TCM is OK.
3.This test checks to see if generator is faulty under load condition. If the voltage is greater than 15 volts, refer to appropriate section.
NOTE ON INTERMITTENTS:Charging battery with a battery charger and jump-starting engine may set DTC 53. If a DTC sets, when an accessory is operated, check for poorconnections or excessive current draw. Refer to circuit for details. Also, check for poor connections at starter solenoid or fusible link.

DTC 53, SYSTEM VOLTAGE HIGH (1993)
DTC 53 will set when ignition is on and PCM/TCM 12-volt battery feed voltage is greater than 19.5 volts for about 2 seconds. During the time the failure is present, the force motor is turned off, transmission immediately shifts to 2nd gear, and TCC operation is inhibited. The setting of additional codes may result.
Test Number1) Normal system charging voltage is 9-15 volts.
Test Number 2) This test checks if high voltage reading is due to the alternator, circuit No. 440 or PCM/TCM. With engine running, check voltage at battery. If voltage is greater than 15 volts, the PCM/TCM is okay.
Test Number 3) This step checks if alternator is faulty under load conditions. If voltage is greater than 15 volts, check alternator.
Diagnostic Aids Jump-starting engine or charging battery may set DTC 53.
If DTC is set when an accessory is operated, check for poor connections or excessive current draw. Also check for poor connections at starter solenoid or fusible link.

from what i have learned (and it may be all wrong)
this error code is a transmission errorcode.
the electronic transmission trips this code because of voltage.

not that that helps me at all.

i am getting closer to spending the 150$ to see if it is the pcm.
i have run out of things to test electrictly short of opening up the wiring loam.

nutz

[Jimmiee]

Try this. Pull all your fuses. Now clear the code and add a fuse, one at a time until the code sets. Then you will know which circuit is setting the code.

[nutpants]

will only 2 fuses in one for the ecm and one for the gauges
i still get code 53 and a bunch more that haynes the haynes manual lists as transmission codes.

nutz

<edit>
ok stupid me. i was checking the plugs on the tranny yesterday to make sure they were plugged in right. that is why i have more error codes now, they were still unplugged when i did the test.
HOWEVER.. none of them reset now with the battery unplugged.
they just dont go away..
so i now have codes of

12 (diag mode/no signal from distributor)
53 (system over voltage)
59 (Trans fluid temp sensor circuit error (high voltage))
81 (2-3 solenoid circuit or solenoid fault. Check solenoid for proper resistance, should read between 20-40 ohms at 20C (68F). )
82 (1-2 solenoid circuit or solenoid fault. Check solenoid for proper resistance, should read between 20-40 ohms at 20C (68F).)

new codes found online have not check manuals yet

so why are the tranny codes not clearing when the battery is disconnected overnight?
(which begs to ask is my code 53 fixed just not cleared?)

nutz

dont know what i was doing wrong but codes have cleared now im back to code 53

[nutpants]

it was the pcm..
just got one from the wrecker and now the code 53 is gone. just flashes 12 over and over.

YEA..


this
""Test Number 2) This test checks if high voltage reading is due to the alternator, circuit No. 440 or PCM/TCM. With [COLOR=blue ! important][COLOR=blue ! important]engine [COLOR=blue ! important]running[/COLOR][/COLOR][/COLOR]
, check voltage at battery. If voltage is greater than 15 volts, the PCM/TCM is okay."""

should read..

Test Number 2) This test checks if high voltage reading is due to the alternator, circuit No. 440 or PCM/TCM. With [COLOR=blue ! important][COLOR=blue ! important]engine [COLOR=blue ! important]running[/COLOR][/COLOR][/COLOR]
, check voltage at battery. If voltage is greater than 15 volts, the PCM/TCM is okay. IF LESS TEST PCM...


nutz
now i need a backup pcm..