deliriousga

I'm at my wits' end with trying to figure out the throttle problem so I'm wondering if the DME itself is messing up. Is there a way for me to test it or do I have to give up and go to a dealer?

I think I've done everything else I can to try and remedy the problem. The E-Gas throttle will not go over 2K rpm and gives me the code P1502. If I clear the code, the car runs beautifully until you turn off the engine and restart it. That's the case whether the engine is cold, warm or hot. I have checked for vacuum leaks and replaced the MAF, O2 sensors, fuel pump relay and throttle body. I don't know what else could cause this problem and go away when the code is cleared unless it's a problem with the DME.

TIA!

99firehawk

uthe fault is for the throttle not adapted
clear the fault
u need to switch on the key not start it
wait one minute without touching anything
shut if off
wait 10 secoinds the ncheck for faults
if the faults present u have a defective throttle body
email me if youd like a wiring diagram

deliriousga

Thanks for the info. I did the adaptation and later replaced the throttle body and did the adaptation again, but it's still acting up. Last weekend I pulled the gas pedal out, took it apart, cleaned it and lubed everything with grease that's safe for plastic/rubber. That didn't work either.

I'm taking the dash out this weekend to see if there is something wrong with the part that the pedal goes to. The gas pedal has a cable that goes to this part in the dash and this part sends the electronic signal to the throttle body to actuate the intake flap. I'm hoping something happened with this part when I was replacing the turn signal switch. Maybe a wire pulled on it or something. That's the only part that has not been replaced between the gas pedal and the throttle body so if that's not it I don't know what to do next.

99firehawk

per the poses diagnostic (not thats thats always right......) that fault only occers on an unadapted throttle body or a tbody with a mechanical fault ill see if can get the whole idea behind it for ya and post it

AlpharettaRK

John-
Are you using a generic scanner? I just invested in a Durametric scanner that might give off some other info, in some cases it will tell you if it is the DME itself. I live not far from you if you want to stop by one day. Or - will you be at Road Atlanta next weekend?
Cheers
Randy

deliriousga

That would be fantastic! I'm not sure if I "have to" take it to a dealer to have the PST2 adapt it or if the key on for a minute, off for 10 seconds is enough for the new one to adapt.

Thanks Randy. I have both a generic scanner and the Durametric and both give me the same code. I love the Durametric since we have a wireless cable connection and it pops up Internet Explorer with remedies for the codes, but nobody has reported anything for this code. I wish I were going to Road Atlanta this weekend, but I'll probably be waiting until fall for Petit LeMans before going. Too much to do around the house right now.

99firehawk

P1502
412 Throttle Jacking Unit, Spring Test – Above Limit
Function
The position of the throttle is controlled by a digital position controller which emits a pulse-width-modulated (PWM)
duty cycle and a direction bit.
After the output stage has been deactivated, the throttle is brought into emergency air position by means of two
springs. This return of the throttle must take place within a certain time. If this time is exceeded, a fault is stored in
the memory.
Diagnosis conditions
– Ignition on (approx. 30 sec.)
– Stationary vehicle
– Engine not running
– Engine temperature > 5 °C
– Intake air temperature > 5 °C
DTC No. Fault conditions Fault area
P1502 Throttle return time too long. – Throttle part
On-Board Diagnostic Troubleshooting
1999 Supplement 3 P1502 - 1
Wiring Diagram
Troubleshooting On-Board Diagnostic
P1502 - 2 Supplement 3 1999
Diagnosis Procedure
Replace throttle part.
Erase the fault memory.
1 Perform adaptation.
End
1 Perform adaptation.
1. Switch on the ignition.
2. Wait one minute.
Do not press the accelerator.
3. Switch off the ignition for at least 10 seconds.
4. Read out the fault memory.

99firehawk

check the return spring then try cleaning and lube the plate and shaft

Tool Pants

On my non e-gas 1997 2.5 there is a fault code for a bad DME, 104. I know because my DME was replaced last year at smog inspection time.

99firehawk

IF IT DOES TURN OUT TO BE A DME THE DME IS COVERED UNDER WARRENTY FOR 8 YEARS 80K MILES

deliriousga

Thanks for the great info. I'll be working on it again this weekend and I'll try this stuff out. Unfortunately, I just hit 83K miles so I hope it's not the DME.

Btw, where is the return spring you mentioned? I took my old throttle body apart and didn't find any springs in it. I'm currently taking the dash out and checking the part that the gas pedal connects to with the throttle cable. Is that where the return spring could be?

Thanks!!

99firehawk

2000 boxster .......................is egas (no throttle cable) (sorry i get confused with all the year changes for difrent things ) .
ill look at one tomorrow and see

deliriousga

Thanks for checking. It does have a throttle cable, it's just a very short one that goes up under the dash to a unit that sends the signal to the throttle body. I'm taking that unit out today to see if that is where the normal throttle spring is located. If so, hopefully I can take care of the problem today.

Thanks,
Joh

99firehawk

that fault should only be thrown with issues at the throttle itself not the pedal assy

deliriousga

I pulled the part out (996.606.115.00) and it seems to be the throttle spring. The throttle cable connects to it and when you let off the pedal the spring inside the part pulls the throttle cable back to idle position. When I twist it like the throttle cable would, the spring makes creaking sounds and it does not return smoothly. I'm going to order the part and replace it later this week to see what happens.

Thanks!!