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Ask -Brad- Your Own Question
-Brad-, Dodge Dealership Tech
Category: Dodge
Satisfied Customers: 7993
Experience:  16 Yrs Chrysler/Dodge Technician. ASE Master Certified(L-1)
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Replaced iac and tps and thought it was cured, wrong. code

Customer Question

replaced iac and tps and thought it was cured, wrong. code po508 came up the third time yesterday before i could get it to reset with scan tool. could a new ignition switch or lube sticky tumbler cause an intermittent failure.. what are your thoughts
Submitted: 2 years ago.
Category: Dodge
Expert:  -Brad- replied 2 years ago.

Before replacing any parts, did you do any diagnostic work or just replace the IAC and TPS trying to fix the P0508 code?

If you have not done any disgnostic's I would start by checking the wiring from the IAC to the PCM.. I attached the wiring diagram to help.. The code you have is:


Check the wiring from ther IAC to the PCM and if it ohms around ,001 the wiring is fine and if that's not a OEM IAC I would try a OEM sensor and if the code still comes back then replace the PCM..

I hope this helps,


  • The PCM senses a short to ground or battery voltage on any of the Linear Idle Air Control (LIAC) control circuits for 2.75 seconds while the IAC motor is active. Two Trip Fault. Three good trips to turn off the MIL.

It means: