Hey guys, I have 2008 BMW 535i with the 3.0l N54 twin turbo engine. My current issue is the car will surge at idle between 1000-1500rpm up-down-up-down-up-down. My code reader shows the following codes:
- P1638 - Throttle Valve Position Control; Throttle Stuck Temporarily
- P1632 - Throttle Valve Adaptation; Adaptation Conditions Not Met
- P3026 - O2 sensor temperature measurement operating temp not reached (Bank 1 Sensor 1)
- P1417 - Throttle Control Incorrect Air Supply (Bank 1)
- P1639 - Throttle Valve Position Control; Throttle Stuck Permanently
- P2243 - O2 Sensor reference voltage circuit/ Open Bank 1 Sensor 1
If I clear these codes while the engine is running, it smooths out and the problem goes away. Stays idling at about 700rpms smoothly for ~10mins then starts acting up again and surging.
I have checked the PCV valve, cleaned oily "MAF"? Sensors before and after the TB (There was a bit of blowby in the intake and it heavily coated these sensors), Checked ALL Fuses I could possibly find, Confirmed Battery Voltage at 12.4V with car off, Confirmed Accelerator Pedal sending input to DME.
I pulled of air box and hoses so I could see if TB butterfly was moving at all while the engine was running and gas pedal being pushed (While issue is present and After codes are cleared) . It would not move at all. My scanner showed that when idle surge issue is present, the computer is not commanding throttle to open. BUT after the codes are cleared and the engine is running smoothly the computer IS actually commanding the throttle to open yet it still doesn't move.
This is most definitely making me believe the TB is the culprit of the issue. I'm looking to confirm my suspicions through the help of this forum and more diagnosis on this car. Also, the O2 sensor B1S1, may be bad? My scanner for some reason wouldn't pull up the voltage for this sensor so I was unable to confirm it's operation and switching between 0-1V.
Quick update: This morning I removed the TB and verified that the TB motor is working. Still trying to find a pin out to test the throttle position sensors in TB
PIN 6 & 2 - 11.4k ohms w/ throttle plate closed and does not change with throttle plate movement.
PIN 4 - No continuity between any other pins
PIN 1 - No continuity between any other pins
PIN 5 & 3 (Motor) - ~8.4 ohms
This is clearly showing an issue with the throttle position sensors inside the TB, correct? But is the motor not on a ‘separate’ circuit that would still allow the throttle plate to move even while the TPS is not reporting back to the ECM?
Hi TMurphey,
I am having the same issue surging that goes away when I clear the codes but comes back when I press the gas pedal, with several codes like you are getting. Were you able to figure out the issue with the car?
Codes
P1408
P1407
DME Boost Pressure control deactivation
DME Camshaft sensor inlet synchronization
DME Camshaft sensor exhaust synchronization
DME - throttle valve actuator jammed (1)
DME - throttle valve actuator jammed continuously (2)
DME - Throttle valve
Several more
Please help.
thanks,
Rey
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