p07xx codes are transmission failures, the FSM covers that
the A/T tranny is complex.
when a DTC sets, that means , TO DO MORE TEST to find the Cause. the ECU can not guess, what is wrong,.ever.
it can only report tests that fail, called, "monitors" OBD2 jargon.
see the great review here (he knows his fact !)
see the 10 tests above link. (fsm tests, they are)
mindless tests. no tech needs this. its just a 2 wire sensor.
if fact a thermistor. NTC type. that is all we need and the trip points.
lets review them all, (really, get the FSM and read it) or alldata.com
0118, ECT reads wrong. engine coolant temp sensor .
with all sensors, its means:
P0118 ECT Circuit High Input
this will cause Limphome
, so must be fixed first !!! low engine power.
the key word there is HIGH, (too high temp, too high voltage
or current) the FSM tells which it is. Voltage, (odd huh? but is true)
on my car this means Open failure
, over 10.4vdc is a hard fail.
- ECT ground wire open
- ECT hot wire open.
- ECT bad, inside its going OPEN circuit.
- its not too hot, as hot is lower voltage !
- its reading insane too cold, that is, colder than possible.
- someone disconncected this sensor with key on. so, reset it.
- Bad ECU, (nah) or wires to ECT , as always, wires can be it.
- the 10 tests above link. (fsm tests they are)
- A short frorm system 12v to the ECT hot wire,
make sure dead cold , rad cap off, the rad if FULL of AF? 50%
is it> that means the ECT is under water.
no ECT works right, dry, nor engine. so check the water first.
no EFI system works right with a Crazy ECT, non do.
so is FIRST ORDER FAILURE.
with cold engine, you off the ECT connector (lock lever !) then
see about 3000 ohms, (see table in FSM)
then put back conn
get engine fully hot.
now off the ECT connector. again.
now reads 300 ohms. (about)
see the ohm change there, 10 for 1.?
300 ohms is about 200 F, see FSM charts for you ambient temp cold.
i never try to guess that. here.
if you connect any scan tool to the OBD2 port you can what
live data from the ECT till the cows come home.
why not do that. see it mess up.
the check the ECT volts key on, and ohms key off.
bingo, the problem is found.
the ECU will not lie to you, it will tell you that is measured.
either a valid temperatures or out of legal range.
in fact the ECU is just a voltmeter, that scales the volts to temperature.
we call this the ECT catastrophic monitor. (out of range)
fix above first.
No other A/T trouble codes set, engine running at cruise speed with VSS inputs received, and the PCM detected the lockup clutch did not engage or disengage correctly.
same as above
4: P1740 (factory code, for same as above 740)
i will not attempt to repeat the 200 pages in the FSM on transmission.
you can read it any time. at alldata.com or buy the FSM.