[cruisermark]

Hello everyone, really hoping someone can help me out here, I've got code P0236, high boost at idle on my 95 powerstroke. I replaced the MAP sensor and hose and made sure that the port on the manifold is clear but I'm still getting the code. I verified ground on pin A, 5 volts on pins B and C of the MAP plug. CEL comes on as soon as I back right off the throttle after having decent boost. Engine runs poorly for maybe 30 seconds and then it resets, light out, running normally. I have to make sure 250 mile trip home tomorrow and I'm not sure what else to do. Thanks.

 

[cruisermark]

Well to follow up i pulled the turbo ducting and checked the turbo and map port on the manifold and everything looks fine. Cleaned the old MAP sensor and no change. I'm going to try to source another MAP sensor in the morning to try unless anyone else has a better idea.

 

[Patrick Feeley]

Not sure if this helps, but here are the pinpoint tests for P0236:

D1 DIAGNOSTIC TROUBLE CODE (DTC) 0236

DTC 0236 indicates a turbo boost sensor A circuit performance.

Possible causes:

-- Damaged MAP hose
-- Damaged MAP sensor
-- Low turbo boost
-- Damaged PCM
-- Intake manifold or crossover leaks

Inspect MAP sensor hose for damage, misrouting or restriction. Is MAP hose OK and free of any restrictions?

Yes: GO to «D2».

No: REPLACE MAP hose. CLEAR DTCs and RETEST.

D2 MAP FREQUENCY CHECK

Disconnect MAP sensor connector.

Connect the MAP sensor tester between the vehicle harness and the MAP sensor.

Connect MAP tester to a DVOM. Set DVOM to frequency scale.

Key on/engine off.

Is frequency reading between 90 hz and 115 hz?

Yes: GO to «D3».

No: REPLACE MAP sensor. CLEAR DTCs and RETEST.

D3 MAP SENSOR PRESSURE CHECK

MAP tester still connected.

Remove MAP hose from sensor.

Key on/engine off.

Using Rotunda Pressure Adapter Kit 014-00761 or equivalent (gauge bar), apply 10 psi of pressure to the MAP sensor. Is frequency reading 145 hz ± 10 hz?

Yes: GO to «D4».

No: REPLACE MAP sensor. CLEAR DTCs and RETEST.

D4 MAP PERFORMANCE TEST

Reconnect MAP hose to sensor.

Disconnect MAP hose from intake manifold and install a pressure (boost) gauge.

Road test vehicle and accelerate vehicle to achieve full boost. Is engine boost 12 psi or greater?

Yes: REPLACE PCM. CLEAR DTCs and RETEST.

No: INSPECT intake manifolds, crossover tubes for leaks. CHECK turbo condition. REFER to appropriate engine section in Powertrain, Drivetrain Service Manual.

Cheers!

 

[cruisermark]

Thanks for the reply. I ended up taking it to a shop which told me they couldn't do OBD1, referred me to a shop that was highly recommend by others as well but couldn't get me in as soon. Anyway, I think shop 1 cleared the code somehow although I thought it happened on the way to shop 2. Shop 2 was unable to see the code or reproduce it, I went and drove the truck with the mechanic and it wouldn't happen. He did pull a "soft" IDM code and #2 injector high resistance code though so I need to do some work on those. It made the journey back just fine. I have heard something occasionally and previously suspected the drivers side wiring which I hadn't changed yet so that was basically confirming my suspension. I guess I'm looking for an IDM as well now though.

Not sure if this helps, but here are the pinpoint tests for P0236:



Cheers!