Commander 3.0 crd limp mode no acceleration problems

[djeffery]

Hi guys, sorry for the slow update but only just had a chance to work on it.

Finally replace the Accelerator assembly as the codes elude to this but as I expected this gremlin is being caused by something else. Limp mode is slowly getting worse but still doesn't do it as much until full operating temp.

Can't seem to get out of my mind that the EGR valve has something to do with it. As I recall, the EGR would only open a bit after you revved the motor. To me it should open as you rev up not down? I did learn from another jeep CRD diagram that the EGR is linked to the accelerator pedal assembly and assume my model would be similar. Was hoping by replacing the assembly would solve this but to no avail....

Does anybody have and ideas as where to look next?

> Something stupid in the gearbox maybe (speed sensor)?
> Maybe swirl motor not faulty but not doing its job causing blow back??
> Corrosion somewhere?
> Can the EGR be bypassed to test my theory???

It is getting to the stage that I wish that drunk driver that went through the lights a few weeks back had collected me

Any ideas would be appreciated

[Clarky]

EGR only opens under 2000 RPM ie round town city driving. No EGR bypass for this engine other then DGE tune.

Time to get your own scan tool I think.

According to the service manual

P2122 code Possible Causes
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K23) APP SENSOR NO.1 SIGNAL CIRCUIT OPEN
(K23) APP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO GROUND
(K23) APP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO THE (K167) APP SENSOR NO.1 RETURN CIRCUIT
(K23) APP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO THE (K400) APP SENSOR NO.2 RETURN CIRCUIT
APP SENSOR
PCM


P2135 THROTTLE POSITION SENSOR
Possible Causes
(K22) TP SENSOR NO.1 OR (K122) TP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
RESISTANCE IN THE (K22) TP SENSOR NO.1 OR (K122) TP SENSOR NO.2 SIGNAL CIRCUIT
(K22) TP SENSOR NO.1 OR (K122) TP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K922) SENSOR GROUND CIRCUIT
(K22) TP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO THE (K122) TP SENSOR NO.2 SIGNAL CIRCUIT
THROTTLE POSITION SENSOR
PCM

I take this to mean P2135 will be triggered when sensor 1 is different to sensor 2

I would concentrate on the P2122 code first as per the manual.

Service manual (WK but drive line is the same)
https://www.dropbox.com/s/tub5m6ked6...e%20manual.PDF

Diesel engine
https://mega.co.nz/#!clQCyTrL!AVYlqV...uYQeZEQG43iU1U

[djeffery]

Wow, Thanks Clarky. You have given me a lot to go on with.

Could you recommend a specific Scan tool? I have a cheap Bluetooth that gives me the codes and I have access to a Scan tool but it is not Jeep specific. I have heard that the merc ones can test/operate actuators individually. I would assume big$?

Anyways thanks again and will let you know how I go...

Daz

[Clarky]

I have 2 that do the job for me.
1 Autoenginuity, a PC based diagnostic program that can read/clear codes & adjust settings .
https://www.autoenginuity.com/

2 Hypertech Speedometer Calibrator (model 752501)
It's primary function is to change tyre size so the speedo is correct but it reads & clears all codes that Autoenginuity can at a quarter of the price.
http://api.viglink.com/api/click?for...FHYP752501.htm

[djeffery]

Ok, decided to have another crack at this as its been parked up for 6 months. Got a hold of a good scan tool as per Clarky's advice and found something new. Still learning how to drive scan tool but found one of the voltages to do with throttle position was staying at 0.4V from idle right up to 2000+ RPM. As soon as foot taken off accelerator then this would spike to around 3.7V then return back to 0.4V again. Weird.... This would however explain the correlation fault codes.
Accelerator assembly already replaced as mentioned so now leaning towards faulty Throttle Body. Problem is, I can't seem to find in my (or Clarky's) manual any info to test this for 3.0L CRD (only petrol models). Do they call this something else maybe?
At first glance connections to pedal and Throttle body seem fine.
Any ideas on how to tackle diagnosis of wiring before lashing out on new Throttle Body?

[djeffery]

Have now swapped over the throttle body and still getting P0122 and P2135.

Only this left is ECU or wiring....

Accelerator assembly replaced before as mentioned

Does anybody know where I can find electrical diagrams for 2007 3.0 crd? (WH, WK, XH, XK)

Particularly between ECU and Throttle body...

Cheers

[Clarky]

Start checking the earthing points for the ECU etc. hotqld has problems with multiple codes & it turned out to be a broken earth.