Code 236

[leeunderwood2000]

What is this code? Can't tell anything but it came up after SES light came on

[More Power]

All of the diesel specific trouble codes can be found in the Member's Area reference.

http://www.thedieselpage.com/members/DTC9698.htm

P0236 Turbocharger Boost System: With the engine off, you should be able to move the wastegate actuator control rod on the turbo up and down fairly easily. A sticky wastegate (due to rusting) can be a problem if vehicles aren't driven for long periods of time.

For any boost related problem, always begin your troubleshooting by measuring the vacuum at the wastegate actuator on the turbo with the engine idling. While most systems will produce approximately 20 inches of vacuum, GM specifies 15 inches of vacuum as the minimum.

If the vacuum is normal, you'll need to check for a ruptured actuator diaphragm. For a simple test, plug the vacuum line back onto the actuator, allow the engine to idle, then try to move the actuator rod with your fingers. At idle, vacuum should be pulling the actuator rod all the way toward the actuator, and it should take considerable finger pressure to move the rod in the opposite direction. If you can move the rod in and out without a lot of resistance, the diaphragm may be ruptured.

If the vacuum is less than 15" at the actuator, measure the vacuum at the vacuum pump. Again, the vacuum pump should be developing a minimum of 15" of vacuum. If not, your vacuum pump will need to be replaced.

Replacement vacuum pumps and vacuum pods are available from both Diesel Injection Service and Gomer's Diesel. Remanufactured pods were about $55 the last time I needed one.

On the other hand, if the vacuum is within specs, but isn't making it to the wastegate actuator, you may have a defective plastic line somewhere between the vacuum pump and the actuator. These plastic lines course their way across the top of the engine to the wastegate solenoid, and pass by several sharp edges on the engine. Look carefully at the entire length of both plastic lines, looking for a wear spot or a break.

Assuming all the prior tests haven't led you to the cause of the problem, the next most likely cause is the wastegate solenoid. This electrically operated solenoid is mounted to a bracket above the driver's side valve cover.

If all the above vacuum system tests haven't isolated the problem, simply replace the Wastegate Vacuum Solenoid (GM part number 1997227, about $29). These solenoids are the most frequent cause of a P0236.

MP

[DA BIG ONE]

Originally posted by More Power:
All of the diesel specific trouble codes can be found in the Member's Area reference.

http://www.thedieselpage.com/members/DTC9698.htm

P0236 Turbocharger Boost System:

If all the above vacuum system tests haven't isolated the problem, simply replace the Wastegate Vacuum Solenoid (GM part number 1997227, about $29). These solenoids are the most frequent cause of a P0236.

MP Followed your instructions, replaced the WVS and that fixed it on my truck!

Thanks

[DA BIG ONE]

Well it worked for a few days at least!

I now have no boost whatsoever.
I have 25 lbs vaccum from the pump to the WSV, but nothing past it.
The line from the WSV is in good shape holds vaccuum when applied.
What controls the WSV, the boost sensor, or?
Also have SES light, haven't had my friend pull the codes yet, any thoughts?

99 GMC SUB 6.5 "F", IC, 3" exhaust, 4wd

[CareyWeber]

Originally posted by More Power:
All of the diesel specific trouble codes can be found in the Member's Area reference.

http://www.thedieselpage.com/members/DTC9698.htm

P0236 Turbocharger Boost System:If all the above vacuum system tests haven't isolated the problem, simply replace the Wastegate Vacuum Solenoid (GM part number 1997227, about $29). These solenoids are the most frequent cause of a P0236.

MP Here is an updated part # 1997255

Carey