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Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 23821
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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2004 Ford Taurus: OBD II..V..I replaced the idle air control valve

Customer Question

I get an OBD II code P1633 and P0511 on a 2004 Ford Taurus OHV engine V-6. I replaced the idle air control valve and still the car has to idle for at least 5 minutes before I can drive. What else could I replace to fix this?
Submitted: 8 years ago.
Category: Ford
Expert:  Steve S replied 8 years ago.
Hi thereCustomer So the car will stall out if you do not let it warm up? As soon as it is warmed up it performs normally? Steve
Customer: replied 8 years ago.

It runs ok but then at times I do get a rough running even at 65.

I sprayed throttle body cleaner and ran sea foam in the tank.

Expert:  Steve S replied 8 years ago.

Hi here are the descriptions of the codes and some possibilities the code 1633 has me interested did you check all of the fuses? The IAC code most likely is a failed circuit to the Idle air control. Have you or do you have the ability to check the circuits? Steve





P0511 - Idle Air Control Circuit Malfunction
This DTC is set when the PCM detects an electrical load failure on the IAC output circuit.
  • IAC circuit open
  • VPWR to IAC solenoid open
  • IAC circuit shorted to PWR
  • Damaged IAC valve
  • PCM damaged
  • IAC circuit short to GND
The IAC solenoid resistance is 6 to 13 ohms. Monitor the IAC PID duty cycle and/or voltage.



P1633 - Keep Alive Power Voltage Too Low
Indicates the keep alive power (KAPWR) circuit has experienced a voltage interrupt.
  • Open KAPWR circuit
  • Intermittent KAPWR
  • Damaged PCM
Loss of KAPWR to the PCM results in immediate MIL illumination and DTC P1633.


Customer: replied 8 years ago.
when i unplugged the idle air control valve and tested with power on but not the engine the dc voltage read around 7.8 mV and no where near 10 to 15 Volts. I am not sure the best way to check the circuit. I do have a multi-meter and could check voltage or continuity. We did replace the battery with a new one. Could that be why the P1633? Thanks, Mike
Customer: replied 8 years ago.
I would be glad to pay the fee if you can resolve my issue. I posted a reply on Oct 3 and now a new one today. Please help. I also replaced the serpentine belt with a shorter one bypassing the air conditioner compressor. I still have the electrical connections plugged in but do not turn on the air conditioner. Could this keep causing my car to have to warm up with my foot on the accelerator for about 5 mins everytime I start the car? I would even consider the next level up Steve if you can tell me what to do to resolve this issue. Thanks, Mike