PO236 Error Code

[dcarver]

PO236 error code, 2002 Dodge diesel 1 ton. 'Turbo Super Boost Sensor A ckt range Perf'. Code is 'Pending'. Has happened twice now. The second time, when driving to local Napa store, at 2,200 rpm, full boost, the herky-jerk occurred. Felt like hitting the rev limiter on the FJR.

Cursory investigation says a possible defective MAP sensor. Hmm, does MAP = manifold absolute pressure? Local Dodge dealer wants $250 for sensor + new harness. The new harness is an upgraded part.

Hey motorheads, am I on the right track with diagnosing this?

TIA -

(gotta have the truck running before the 'Gathering of the clan' Morro Bay ride/campout!)

 

[UweRoss]

Yes, MAP = Manifold Absolute Pressure, and indeed P0236 points right at that sensor.

The MAP sensor is pretty important on a turbo-diesel. When the ECU detects a fault with it, it's gonna go into limp mode, meaning boost (and fuel) get limited to low (safe) values so that the engine doesn't go "boom". If the problem is intermittent, you can probably get it out of limp mode by shutting the motor down and re-starting it.

If there's an updated/upgraded harness, they know there's an issue. Question is if the problem is indeed the harness, why they want to sell you a new sensor as well? I suppose it's possible that the problem is actually at the connector to the sensor and that whatever re-designed connector they are using won't fit on the old sensor.

-Uwe-

 

[twowheelnut]

I bet that old pick-up used to haul firewood around Carvertown never had an error code.

 

[dcarver]

Yes, MAP = Manifold Absolute Pressure, and indeed P0236 points right at that sensor.
The MAP sensor is pretty important on a turbo-diesel. When the ECU detects a fault with it, it's gonna go into limp mode, meaning boost (and fuel) get limited to low (safe) values so that the engine doesn't go "boom". If the problem is intermittent, you can probably get it out of limp mode by shutting the motor down and re-starting it.

If there's an updated/upgraded harness, they know there's an issue. Question is if the problem is indeed the harness, why they want to sell you a new sensor as well? I suppose it's possible that the problem is actually at the connector to the sensor and that whatever re-designed connector they are using won't fit on the old sensor.

-Uwe-

Thank You. Any possibility the new harness provides distance from the manifold to prevent heat damage to the sensor? Just wondering.. and am I stuck at buying a factory sensor? And/or harness? Given the truck is 6 years old, and this is the first failure, I'd be more than happy another 6 years of service, minus the harness cost..

I bet that old pick-up used to haul firewood around Carvertown never had an error code.

Absolutely correct Tim. Old Blue (84 4wd F250, 460 gas motor) has never ever thrown an error code. Or left me stranded. Long live old 8 mpg old blue!

 

[huk finn]

clean contacts in sensor plug wiring first, maybe some corrosion. check wiring to sensor for any shorts. Check vaccum lines (if you have them ) to wastegate.

It could be your sensors still good, wastegate malfuntion

 

[Hit the Road Jack]

It might be worth trying to disconnect and reconnect the battery and see if the fault code 'resets'.

HYCLE can likely provide you some professional council.

 

[huk finn]

you can sign up with this forum, ask question. Usually get some answer in a day or 2. Give all info on truck & engine model.

https://groups.msn.com/AutoTechsOnline/messageboard.msnw

 

[HYCLE]

It might be worth trying to disconnect and reconnect the battery and see if the fault code 'resets'.
HYCLE can likely provide you some professional council.

I will check for Factory Technical Service Bullitens, TSBs, at lunch today. I will let you know what I find.

Sometimes a new harness is needed when the part is made by a new supplier or when the connector is improved.

 

[HYCLE]

I will check for Factory Technical Service Bullitens, TSBs, at lunch today. I will let you know what I find.

No TSBs for this code.

You can check boost pressure after clearing the code. If it sets a code and the boost pressure is correct then changing the map sensor makes sense.

Mike

SYMPTOM

P0236-MAP SENSOR TOO HIGH TOO LONG

WHEN MONITORED

Engine running.

SET CONDITION

Boost pressure signal indicates boost pressure is high when other engine parameters (i.e. speed and load) indicate boost pressure should be low or boost pressure is low when other engine parameters indicate it should be high.

POSSIBLE CAUSES

Other codes

Checking boost pressure sensor

Checking the 5-volt supply circuit

Sensor ground circuit open

MAP sensor

MAP signal circuit open

MAP signal circuit STV

MAP signal circuit STSG

MAP signal circuit STG

ECM