P0069 and P1854 problem

giacomo.m · **Posted:** Mon Apr 11, 2022 9:58 am

Hi all,
i have this 2007 KJ 2.8 CRD that for some time has these error codes : P0069 - P1854 no limp mode
I have already replaced MAP sensor and Intake air pressure sensor ( A0061539828 Mercedes ) I also checked the connectors and electrical cables, and everything seems to be in order, but to no avail.....
can someone help me ?
thank you

Giacomo

WWDiesel · **Posted:** Mon Apr 11, 2022 1:55 pm

If all connections at sensors are verified good, and you have replaced both sensors with new OEM sensors (Not some cheap chinesium knock offs), and you have checked and verified that all the wiring between the sensors connectors all the way to the ECM is in good shape. No broken or chafed wiring anywhere on the harness.
Have you inspected the wiring harness where it passes behind the fuel filter mounting, a known chafing spot on 06's, 07's may have the same issue???
Another known chafing spot is where the harness passes under and behind the alternator mounting bracket going over the top of the engine.
Have you checked all grounding locations like the one behind the left front headlamp on top of the inner fender? A bad ground can cause some problems.

Have you disconnected and checked the connection pins where the main harness plugs into the ECM?
Look for any discolored or corroded pins.

Using the FSM (factory service manual) wiring diagrams, you can back probe the connectors for both of these sensors and check for the 5v reference signal and for a good ground signal.

giacomo.m · **Posted:** Tue Apr 12, 2022 2:30 am

Thank you WWDiesel
Map sensor : 68031593AA Crown
Intake Air Pressure Sensor : A0061539828 Mercedes
connections at sensors good, i must verify all the wiring between the sensor connectors all the way to the ECM even if it will be a problem as you will have to open all the big main wiring ....
do you have a diagram of all the ground locations on the jeep ?
the back probe the connectors of these sensors for check ground signal must it be done with the connector attached to the sensor ?
with the red probe of the tester on the wire and the other on the ground of the engine, what value should I read ?

Giacomo

WWDiesel · **Posted:** Tue Apr 12, 2022 11:46 am

Don't use Crown parts, they are known junk!
You don't have to open up the harness, simply backprobe the each power and ground wire one at a time with the connector disconnected from the sensor using an ohm meter.
This will tell you if you have a broken wire inside the harness or a power wire shorted to ground.
You can also test the + power 5v wire using a volt meter (key on) at the sensor, this will tell you if the power wire is broken or has a bad connection from the ECM.

All the grounds are shown in the FSM, here is a link to the on line manuals:> http://www.colorado4wheel.com/manuals/Jeep/KJ/

Grounds:

giacomo.m · **Posted:** Tue Apr 12, 2022 12:51 pm

I checked the mass behind the left front headlamp and the connections pins on the main harness plug into ECM and they don't seem discolored or corroded
so do you think it is better to replace the Crown with some other spare part ?
do you have any alternatives besides the Mopar ?
to check the wiring, do you mean one probe of the tester on the power or ground cable and the other probe on the corresponding cable on the control unit connector to check continuity ?
thanks again

Giacomo

20220412_115719.jpg

WWDiesel · **Posted:** Tue Apr 12, 2022 1:52 pm

giacomo.m wrote:

I checked the mass behind the left front headlamp and the connections pins on the main harness plug into ECM and they don't seem discolored or corroded
so do you think it is better to replace the Crown with some other spare part ?
do you have any alternatives besides the Mopar ?
to check the wiring, do you mean one probe of the tester on the power or ground cable and the other probe on the corresponding cable on the control unit connector to check continuity ? YES
thanks again
Giacomo
20220412_115719.jpg

Yes, replace the Crown part, it could be part or all of your problem.
You can use the GM MAP sensor (made by Bosch), many of us are running it. Much cheaper than the OEM Mopar sensor.
GM 55206797 (about $20 bucks US dollars)
New GM PN; 55568175
Google the part numbers.

Are you close to Marco Giacomelli who is in Northern Italy? He may could help you diagnose the problem.
You can contact him on this forum, aka "Yeti", using the email or pm buttons at the bottom of one of his posts.
or
message him over on Facebook at:> https://www.facebook.com/YetiChiptuning

giacomo.m · **Posted:** Tue Apr 12, 2022 3:33 pm

ok i will buy 0281006076 Bosch sensor
I am not close to Marco Giacomelli as I am in Rome, once I have already tried to contact him using pm button with no answer, but now I will try again ....
thank you

Giacomo

giacomo.m · **Posted:** Fri Apr 15, 2022 7:28 am

I replaced Crown Map sensor with 45962082F VM (0281002845 Bosch ) but the problem is not solved
could it not be the baro pressure inside the ecm ....?
thank you

Giacomo

WWDiesel · **Posted:** Fri Apr 15, 2022 3:29 pm

giacomo.m wrote:

I replaced Crown Map sensor with 45962082F VM (0281002845 Bosch ) but the problem is not solved
could it not be the baro pressure inside the ecm ....?
thank you
Giacomo

Are you still getting the same two codes?
Have you checked the connections and wiring to the small pressure sensor on the side of the airbox? It could be the root of your problems.
P1854 -- Airbox pressure sensor error (sensor malfunction or possible bad connection)

giacomo.m · **Posted:** Sat Apr 16, 2022 2:16 am

Yes i always have the two error codes: P0069 and P1854
I will check again the connections and wiring to intake air pressur sensor....

Giacomo

giacomo.m · **Posted:** Sat Apr 23, 2022 2:58 am

Update :
I checked the 3 wires of the intake air pressure sensor, everything is ok
all three have continuity and there are the 5V of ECU
the symptoms are these: the jeep has lost power, the engine has no grunt, max speed: 130 Km / h at 3000 rpm, 2th gear / 3th gear / 4th gear max 2330/2500 rpm .....
in addition to the p1854 now there are p0045 - p2294 - p0090 - p0193
Help....

Giacomo

WWDiesel · **Posted:** Sat Apr 23, 2022 12:23 pm

These are the codes you listed, looks like you have a short to ground and / or broken wires.
Need to check all your wiring harnesses. Some of the codes points to wiring issues.

circuit open Wiring

open circuit Wiring open circuit

high input Wiring short to positive

giacomo.m · **Posted:** Sat Apr 23, 2022 12:54 pm

Nooooo, pharaonic enterprise, it's like looking for a needle in a haystack .....
do you need to open the large wiring from the ECU to the top of the engine ?
thank you

Giacomo

giacomo.m · **Posted:** Mon Jun 06, 2022 8:41 am

Hi,
someone knows the Bosch part number of airbox pressure sensor( mercedes ) ?
thank you

Giacomo

WWDiesel · **Posted:** Mon Jun 06, 2022 12:14 pm

giacomo.m wrote:

Hi,
someone knows the Bosch part number of airbox pressure sensor( mercedes ) ?
thank you
Giacomo

IAP sensor – OEM part no.: 05101120AB
(intake air pressure sensor on side of airbox)
air inlet air pressure comparator pressure sensor on the side of the air box;
sometimes referred to as the “Mercedes sensor”
• Bosch part no.: 0261230189.
• Mercedes OEM part no.: A0051535028
• Autozone part no.: 0261230189

giacomo.m · **Posted:** Mon Jun 06, 2022 4:02 pm

WWDiesel wrote:

giacomo.m wrote:

Hi,
someone knows the Bosch part number of airbox pressure sensor( mercedes ) ?
thank you
Giacomo

IAP sensor – OEM part no.: 05101120AB
(intake air pressure sensor on side of airbox)
air inlet air pressure comparator pressure sensor on the side of the air box;
sometimes referred to as the “Mercedes sensor”
• Bosch part no.: 0261230189.
• Mercedes OEM part no.: A0051535028
• Autozone part no.: 0261230189

that's perhaps where the problem lies
a few days ago I told you I had mounted the A0061539828 (Mercedes )but no one told me that instead the sensor to be mounted is A0051539828...
tomorrow I try to fit : 0261230189 Bosch and let's see how it goes

Giacomo

P0069 and P1854 problem

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