Need Automotive Tech help please (Honda Pilot)

[Lee_Burough]

I'm selling a 2003 Honda Pilot with 64k miles and suddenly have some drivability problems and a couple lights. Please help me sort this out.

Vehicle has been rock solid performer all this time, with all the dealer services. Has set unused for a couple weeks. After a stop at the gas station, the Malfunction Indicator Lamp & the VTR-4 Lamp came on and stayed lit. The engine idle RPM hunts rapidly between 800-1500 RPM for a minute after warm start and then settles down, but still hunts more than it should....No miss apparent.

Do these symptoms match anyone's experience? Where should we start?

TIA

 

[Bens87tr]

Scan it with an HDS. That VTM-4 light can be set off because of the Check engine light, just get a code for that CEL.

 

[Bens87tr]

found this... get me a code and I can help you get started

Idle Fluctuation With DTC P1129
SYMPTOM
The idle fluctuates, and the MIL is on with DTC P1129
[high manifold absolute pressure (MAP) sensor signal]
set.
PROBABLE CAUSE
The idle air control (IAC) valve is faulty. The IAC valve
sticks open and creates a higher manifold pressure
than expected, causing DTC P1129 to be set before
P0505 (faulty IAC valve) is registered.

 

[Lee_Burough]

Scan it with an HDS. That VTM-4 light can be set off because of the Check engine light, just get a code for that CEL.

Thanks Bens87tr, I assumed some sort of cascading series of lights....Will try to get a code reader on it. Is there a way to read them manually?

lee

 

[Lee_Burough]

Idle Fluctuation With DTC P1129
SYMPTOM
The idle fluctuates, and the MIL is on with DTC P1129
[high manifold absolute pressure (MAP) sensor signal]
set.
PROBABLE CAUSE
The idle air control (IAC) valve is faulty. The IAC valve
sticks open and creates a higher manifold pressure
than expected, causing DTC P1129 to be set before
P0505 (faulty IAC valve) is registered.

Now thats just what I need :biggrin: Thanks!

Do you think cleaning the valve would limp by for a while?

 

[Bens87tr]

It could, that is still just a guess on what the problem is. I went on the Honda network and searched by vehicle and typed "idle", that was the only bulletin that popped up with your symptoms. No way of getting codes manually, should be able to get a free scan at autozone.

 

[Lee_Burough]

Ben, The code was P0505 "Idle Control Malfunction" (Good Call!)

There was another code, but it reset before I could read it (code reader said there were two codes when I first plugged it in). Autozone cheat sheet suggested these likely causes for P0505: Vacuum leak, faulty IAC, Dirty Throttle Body, or poor IAC power connection (thats all I remember).

What I did: Sprayed some top engine cleaner into the IAC airway (hoping to clean and lube IAC)....No difference, Checked fuel cap for good seal (the whole episode started after refueling), Checked coolant full (a bare coolant sensor can make idle problems), Inspected vacuum hoses and didn't find any indication of age whatsoever, Disconnected the IAC plug and reconnected it (no codes after that). Then, Disconnected the Battery and cleared the code. I think I' spray some cleaner in the throttle body in case that might help.

We'll drive it a couple days and see....I don't think I changed anything that would stop the code in the future. Thanks for your help on this. :biggrin:

 

[Bens87tr]

Glad I could help. I've got more info if you need it to troubleshoot those codes.

 

[kh440]

The Acura MDX uses the same drietrain, and we sell quite a few IAC valves (rotary control valve in Honda-speak) cleaning will buy som etime, but don't be surprised if the problem comes back. There is a new and improved design available now for about 85.00

 

[Lee_Burough]

The Acura MDX uses the same drietrain, and we sell quite a few IAC valves (rotary control valve in Honda-speak) cleaning will buy som etime, but don't be surprised if the problem comes back. There is a new and improved design available now for about 85.00

I appear to have bought some time I'll inform the new owners of this episode so they will know to buy the new and improved rotary control valve. Thanks

 

[GoldT]

Call your nearest Honda dealer and find out what the emissions warranty is-some items are covered for 8 years or 80000 miles under federal law. Just ask for someone in the service dept. who is knowledgeable about warranty time and mileage limits.

 

[Bens87tr]

That would be me.....

It is not covered under any emissions warranty.

Intake Air System
Throttle Body (including Throttle Position
Sensor) . . . . . . . . . . . . . . . . . . . . . 3/36
Idle Air Control Valve . . . . . . . . . . . . . . . . 3/36
Intake Air Resonator . . . . . . . . . . . . . . . . 3/36
Air Cleaner Housing. . . . . . . . . . . . . . . . . 3/36
Air Cleaner Housing Cover . . . . . . . . . . . . . 3/36
Air Cleaner Element*2 . . . . . . . . . . . . . . . . 3/36
Intake Air Ducts . . . . . . . . . . . . . . . . . . . 3/36
Intake Manifold Assembly . . . . . . . . . . . . . . 3/36



Unless you live in CA, VT, or MA. Then it's 7/70...

 

[Lee_Burough]

The Pilot is running fine with no codes....I informed the new owners and they will know what to do when and if the time comes. Thanks for the help