free hit
error code P2173?? - Engine & Ancillaries/Gearbox - The Lotus Forums #ForTheOwners Jump to content

error code P2173??

Recommended Posts

Sorry if this has been covered here already but Ive fault codes P2104 (which I've already found out is throttle control unit) and P2173 which I cannot find what it is.

Does anyone on here know what this fault code is for?

keep getting a misfire, well almost an ignition cut when really on it. Its like the ignition is cut just more a millisecond when powering out of a corner. Its sufficient to unsettle the car, but only occurs when you're really pushing on.


Link to comment
Share on other sites

Upgrade today to remove Google ads and support TLF.
  • Replies 5
  • Created
  • Last Reply

Top Posters In This Topic

P2173 Throttle actuator control system – high airflow detected
Description The mass air flow is compared with the throttle position to determine whether an incorrect correlation exists.
Enable Criteria: •    None
Disable Criteria: •    MAF    fault(s)    present
Potential failure modes: •    Throttle    plate    damage •    Air    leak    in    intake    system
Notes: A mechanically sprung 7% throttle opening may be imposed, or the injectors may be shut off to stop the engine.


Did you try disconnecting and reconnecting the throttle body connector?  No air leak?  Still on stock airbox?  Clean MAF?  Check MAF connector?


I guess the above note on the injectors shutting off might be what you describe that feels as an ignition cut?


The P2173 is the actual fault, P2104 is the ECU "fail safe":


P2104 Throttle actuator control system – forced idle 
Description If a problem is detected which could result in faster engine speed than commanded by the pedal, the actuator is switched out, allowing the throttle valve to default to a 6% mechanically sprung setting.  This provides a fast idle speed which may be used to effect a 'limp home' mechanism.
Monitor: •    Continuous
Enable Criteria: •    Engine    running
Disable Criteria: •    None
Potential failure modes: •    Electronic    throttle    fault
Note: This code indicates action taken by the ECU, and will always be accompanied by another code which has caused this action.


Edited by Kristof Thys
Link to comment
Share on other sites

Thanks  Kristof,

I'm no mechanic, and everything is stock but I will try what you suggest, disconnecting and reconnecting the throttle body connector. I'll check for any obvious air leaks and clean the  MAF and connector?

Its so intermittent its difficult, to tell if I've solved the problem. 

Link to comment
Share on other sites

  • 2 years later...

I'm dragging up old topics again!!


This exact situation and same codes happened to me tonight. 

Died and wouldn't start in middle of busy junction.

I unplugged throttle body, intake etc, put it all back together, starts again but doesn't run perfectly and if you try and rev match into a lower gear, she will hesitate before responding..... 

Did you manage to sort it Dunsfold Dave?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Upgrade today to remove Google ads and support TLF.

  • Create New...