2004 Isuzu Rodeo 3.5L P0300 code

Link to a reasonable explanation of the code and suggestion of checks below...

https://www.obd-codes.com/p0306

does it have spark ? pull a plug wire an check , does it have fuel pressure ? Did you do the diagnostic test's for each code ?
2001 isuzu rodeo CEL light codes P1515 P1295 P1125

replace no 6 injector
check injector wires and connections

no engine stated.
answering for usa rodeo. only. on a usa forum.
it means trouble; the factory manual covers this.
As does mitchells DIY online, read that much>?
those are called DTCs , scan codes. diagnostic trouble codes.
The PCM looks for problems all the time running,
CALLED MONITORS (a sort of nanny)
all cars do this 96 to now, in USA. by law.
If no book or no mitchells try google (or the like)
if you had you'd have seen isuzu examples.

but google finds this in 1 click.

the great justanswersl.com (ASE Techs)?
1125
1295
1515
DTC P1125: ELECTRIC THROTTLE CONTROL (ETC) LIMIT PERFORMANCE MODE.
2nd hit.,
P1125 Isuzu Electronic Throttle Control Limit Performance Mode P1221 Isuzu Throttle Position Sensor 1-2 Circuit Performance P1295 Isuzu Electronic Throttle Control Power Management Mode P1515 Isuzu TP Sensor To MAF Sensor Correlation


the first hit said, bad grounds top engine to PCM
and bad harness wires to above same place.
but as all techs, no, bad wires, happen all the time.
as do vast other reasons.
what I do , as the FSM states, clearly
is pick one failure and correct it, and sometimes gets them all.
like blown fuses do, on all vehicles.

1125 means limphome, is in force Low power too.
the TPS is acting up.
the 1515 means in English
that the Throttle angle and air flow dO NOT JIBE.
my jeep books calls that "incongruity": (nicer word)
or they differ. and should not.
i'd be checking the TPS voltages. for correct voltage.
this can fail for wires, rust, and bad sensors.
the word performance means it reads funny. (wrong)


we use a real scan tool and a real volt meter to see what the readings are on these parts.
why not get a real ASE tech to find it.
they know all that electronics magic,
ALL learn that there can be false codes.
one failure can trip many codes, but only one is the fundamental code.

or vacuum leaks cause many errors but not one
states vacuum leaks.
see?

get check engine codes pulled if u have codes p0300-p0306 check ur spark plugs and or coils and boots and check to see if ur running the correct engine oil for that engine

so missfire detected and cylinder 3 missfire detected.
check to see injector pulse with "noide light" if ok injector is problem
remove fuel rail and injectors look into top of injector for blockage in screen filter in injector if blocked clean out or injector carby places can remove this screen replace it and test injectors and clean or just buy new injectors. make sure to clean out fuel rail and change fuel filter also.
if noide light flashes irratic or not at all wiring issue, check for power on one wire with ignition on 12v other is earthed by ecu when opened to inject fuel. other thing that can cause problem on cylinder is tappet clearance "shims" too tight, could do compression test to see if compression is low on cylinder or a cylinder leakage test to see if valves are leaking. broken valve spring. valves do not hit piston on these engines even if cam belt breaks, they are a "free wheeling" engine

p1125 tells you the vehicule has gone into (limp) mode or reduced power. p1295 will direct you to a problem with your Throtlle position sensor and p1515 fault indicates theres a problem with the corilation between throttle position and commande giving.

i own a 2001 rodeo LS 3.2L and had this codes show up. The machine had really bad idling and when accelerating quick after first start would go into limp mode and not pick up speed pass 50 kms. i tryed changing the throttle position sensor.. nothing. tryed changing the spark plugs and noticed they looked unusually white (engine running lean) i put injector cleaner in with i freash tank of gas thinking the injectors were dirty and it seemed to help. Next a changed the fuel filter which completly solved my problem. at the last oil change they told me they changed it but didn't the inside of the filter was rusted and clogged starving the engine of fuel.

Problem solve for 15 $ after you change your filter take it to and auto parts store with a computer to reset the engine lights

that code is for a multiple or random missfire.i would check or just replce if its been awhile the spark plugs and wires fuel filter also if its been awhile

After market spark plugs could be the problem.
Reinstall the old plugs and see if that fixes it.
This vehicle has an ion sensing ignition system and is real sensitive to the proper spark plugs. I would get the proper plugs from the dealer if the old ones work.
The codes P1311 and P1312 are ion sensing codes.

means you have multiple misfires (po300) the other codes are lean codes, possiable tune up , bad injector, fuel pump,