Low R.P.M.

[mateito505]

Hello everyone,

I have a Chevrolet Vitara 2007 (Colombia - Latin America retail), in essential it is a Suzuki Sidekick.
It has a G16B engine (1.6L@16V). 4wdor 2wd, 2doors or 4, what transmission, auto or stick.?


I'm writing this post because I'm having some issues with my car when I turn on headlights or defrost.\
Sometimes when I did that the ECU can't regulate the R.P.M to ~800 and the revolutions fluctuate between 400 or 500 while the car is stopped (idle), other times the ECU can regulate the R.P.M without problem. I'm going crazy with this problem.
I already clean and check the TB, I did special emphasis in the ISC valve. (This problem happen regularly)
The ISC is offline ,or jammed.
The purpose of the ISC (its a slave of the ECU , 100% so) is to hold hot idle at 800rpm, and in gear, if automatic
the worst case is with automatic, in neutral shift to drive and a huge load goes on to the engine, (via the TC clutch drag is HUGE)

The first step you skipped, scanning the ECU , why skip step 1 on all cars, with EFI>?
if there ECU shows P0xxx errors, DTC errors, know and learn that some are limphome mode, and there are no idle controls in limphome mode
so that is why you always must scan any cars engine first, to see whats wrong, first. guessing is impossible here, see why?
P0400 EGR failure? oops.

Another issue with my car (probably it is related to the first problem (IT IS)) is when I am driving the car in the highway during 20 minutes in constant speed and when I have to stop because of a traffic light or traffic jam in the city... in that moment when the car is stopped (idle) or I'm not touching the accelerator and the car is in neutral gear (ISC is working), (are you really in Neutral driving at a light? stopped? why? never seen anyone do that. (but saves fuel it does)

the R.P.M fluctuates between 400 and 500 again...
also EGR stuck open causes 400rpm this is the all time #1 cause. clean the EGR main or replace it.

And sometimes the car turn off abruptly. the word is STALLS, engine stalls.
and 99% of time the EGR main is this cause.

When it happens I turn off and turn on again the car and it goes to work properly again. (This problem happen 2 or 3 times per month)

What can I do to fix those problems? (FPR related problem?, TPS calibration? (no such thing in 2007), anything else?)

Someone tell me about a bad diode in the headlights circuit. but I haven't idea... your friend is off base, sorry, there is no diode in any 2007 car, his was an 1988, a whole other car and electrics. what he meant to say is 1989 car has diode bock on the ECU that is a (wired OR logic gate)
that raises idle to 1000rpm head lamps on, this diode ended 29 long years ago.


Thanks in advance.

the ISC also prevents all stalls
it opens the ISC wide open and no stalls possible. EXCEPT (there are other reasons, but...)
But if the EGR sticks open it stalls or runs 400 rpm and shakes like wet dog, misfiring like MAD, you can even see the engine shake hard.

Sorry about car's information. It is a 2-door and 4wd with manual transmission.

Sorry again, but I don't have an ECU scanner at this moment, trust me it would have been my first step.
Although I have a question at this point. If I had a problem like P0400 EGR Failure.. Should be the check engine light on or not necessary?

On other hand, What do you mean when you said "The ISC is jammed"? What can I do to fix that?

What is your recommendation to clean the EGR main?

Thank you so much for your time and recommendations.

Mateo