Two replacement ETMs installed in last 10k miles. Still surging?

[briangtbc]

I picked up a 1999 V70 T5 last week on eBay. A buddy with a 1999 V70 T5 warned me about the ETM issues and suggested I make sure this wasn't an issue with this car. The seller self-installed a rebuilt ETM just before selling the car at 177k miles. Looking through the extensive service records that came with the car, I noticed another owner of the vehicle had the ETM replaced at 167k miles.

Currently, I'm experiencing surging of the throttle, primarily when in gear in either R or D, occasionally while in P. No ETS or Check Engine service lights are on.

The seller has a contactless throttle body sensor kit that he purchased and installed prior to the latest ETM replacement, hoping that would fix his issue. But when it didn't, he removed it and just replaced the ETM. Right now, the plan is to remove the ETM and install the contactless sensor. I'm hoping that will fix the surging, but I'm worried about this car having two new ETMs so recently and still experiencing the surging issue. Any other things I should check before getting into the ETM?

[RickHaleParker]

Any other things I should check before getting into the ETM?

Get a Diagnostics Scanner and get better diagnostics info. A DiCE clone and Vida 2014D_RePack is recommended.

[briangtbc]

Grabbed an old OBD scanner I had and pulled P1238 code. Research says that is related to turbo control valve. Possible vacuum leak or bad TCV?

[RickHaleParker]

P1238 = ECM-6806 Turbocharger (TC) control system flow fault. Flow too low or too high. Permanent/Intermittent fault


Diagnostic trouble code (DTC) information

Condition
If engine speed (RPM) is above 3500 rpm and the engine is operating at a high load, the control signal to the turbocharger (TC) control valve is at maximum and the boost pressure (from boost pressure sensor) is lower than a designated value (approximately 20 kPa (2.9 psi) under normal boost pressure - signal too low).
If the air mass (from mass air flow (MAF) sensor) is higher than a desired value (signal too high) it is interpreted as a fault and diagnostic trouble code (DTC) ECM-6806 is stored.

Substitute value
reduced boost pressure

Possible source
Signal too high:

• 1. air leakage after turbocharger (TC)

Signal too low:

• 1. hoses between turbocharger (TC) and turbocharger (TC) control valve respectively turbocharger (TC) control valve and pressure servo are loose or are blocked/damaged
  2. faulty turbocharger (TC) control valve
  3. faulty boost pressure control (BPC) valve pressure servo
  4. sticking boost pressure control (BPC) valve

Fault symptoms
none

[abscate]

Flippers will try to fix the car long enough to sell it to the mark with a cheap fix. Just cleaning an ETM can get you a few weeks of operation , enough for the seller to justify the year fixed it.

History check on any car is paramount, and if the seller hasn’t transferred title, assume you need a $1000 ETM and take it off wholesale price.