as the title says, does anyone know what code 1508 means for an obd2 gsr???

 

Search option is there and I found a whole list of OBD2 codes within 120 seconds. https://honda-tech.com/zerothread?id=466877 Unfortunatly, theres no description for p1508.

edit: Even better, I googled OBD2 p1508 because I was curious and found it even quicker.
P1508 Idle Air Control (IAC) System - Low RPM

 

Hey HT -

I found this thread through searching as it's the best match to the issue I'm trying to tackle.

The car - 97 Integra LS w/a B18C1 swap. Stock OBD2a harness. 98 GSR ECU. Edelbrock Performer X IM (no IAB), stock TB/TPS/MAP

I've been getting DTC P1508 for a few weeks now and am at my wits end. So far I've gone through the Helms manual and have ruled everything out in the flowchart.

Specifically...

-ECU reset - no change

-Disconnected the IACV connector. Put the key at II in the ignition. There is 12v between IACV connector pin 2 and chassis ground.

-12v between ECU pin A12 (disconnected) and chassis ground. Key is at II.

-Connected a jumper wire between A10 and A12 with the key at II. I can hear the IACV click open/close.

-I removed the IACV and connected the pos/neg ends to the battery. Again, I can see/hear the solenoid move. I have also tried a second IACV and got the same results.

-Verified continuity between ECU A12 and IACV pin 1.

-Tried my original 97 LS P75 ECU (a, "known good ECU")... same damn code.

-Confirmed that all the connectors are plugged in the correct slot. The IACV is 2-pin. The TPS and MAP are 3 pin. The IAT is on the back side of the intake. On the stock LS IM, the IAT is near the runners for cylinder 1, so it's nowhere close to the IACV and impossible to mix up.

I have adjusted the throttle cable so the car idles around 500-700rpm once it's warm. The car has a erratic idle once it's there. The idle adjustment screw is pretty badly seized up, so I made a slight adjustment to the throttle cable to compensate for it.

What else is left for me to try?!?!

 

bump... anyone??

 

try bleeding your coolant system to see if it helps..also check your wiring. it could be electrical issue

 

replace iacv, thats what i did when my went bad.

 

already replaced it. same result.

Hooked both IACVs to the battery and confirmed they click open/close when you apply 12v.

Question - how much is the valve supposed to move?? A few millimeters or 1-2 inches?

 

Same issue here..did u ever fix it..need .to kno Plzz