hard to start

flash7210 · **Posted:** Tue Sep 17, 2019 2:23 pm

WWDiesel wrote:

flash7210 wrote:

The 05 and 06 CRD alternators and wiring are exactly the same.
That one small gauge wire connects to the voltage regulator.
All that one wire does is excite the field.
In most cases, that one wire can be disconnected and the alternator will continue to charge just fine. Inside the regulator is a capacitor and as long it has some charge in it will support the excitation.
(I know this because I repaired my alternator by replacing the regulator and disassembling the old regulator)

Good to know, same as the "One Wire" GM alternator used in many older applications when updating from a generator to an alternator.
Have installed a many of the GM One Wire's on old tractors, trucks, cars, etc.

Do you happen to know what the voltage is going in to excite the field? Is it 12v like the GM units?

Well, it’s not more than 12 volts.
It would make sense for it to be 12 volts.

And yes, there is the possibility that it will self excite at a certain RPM just like the GM 1-wire alternators.
When I fixed my alternator I left that wire disconnected. Then I started the engine. Then when at idle I connected the wire and noticed the increased load on the engine.

TKB4 · **Posted:** Tue Sep 17, 2019 3:23 pm

Not sure when last 2006 CRD was built but assume started about 9/05. The one I looked at was built 2/06.

Billybob · **Posted:** Thu Sep 19, 2019 3:21 am

Keith from GDE once wrote up a report on how the charging of the 2005 and 2006 CRDs work...I cannot find this at the moment but I believe that the 2005 model Alternator gets its field operated by a pulsed square wave signal that energises the field. This is know as PWM..Pulse Width Modultion..whereby the ECM increases the length of the square wave to increase the current output.

The 2006 CRD has its regulation built into the Alternator..the single wire just wakes up the alternator to starts its internal regulation. At startup the alternator is not woken up...so as to place less physical resistance to the starter motor. Once the engine has fired the alternator starts to regulate itself.

I may be wrong about the above..we need Keith to confirm this! :wink:

WWDiesel · **Posted:** Thu Sep 19, 2019 3:58 pm

Billybob wrote:

Keith from GDE once wrote up a report on how the charging of the 2005 and 2006 CRDs work...I cannot find this at the moment but I believe that the 2005 model Alternator gets its field operated by a pulsed square wave signal that energises the field. This is know as PWM..Pulse Width Modultion..whereby the ECM increases the length of the square wave to increase the current output.
The 2006 CRD has its regulation built into the Alternator..the single wire just wakes up the alternator to starts its internal regulation. At startup the alternator is not woken up...so as to place less physical resistance to the starter motor. Once the engine has fired the alternator starts to regulate itself.
I may be wrong about the above..we need Keith to confirm this! :wink:

If that is the case; mighty strange that the parts stores list the same part number for both 05 & 06 CRD alternators. :shock:

Billybob · **Posted:** Fri Sep 20, 2019 4:41 am

Yeah I agree that they seem to have the same PN

Keith may have been referring to a Gasser setup versus a CRD setup...I cannot find the post in question.

WWDiesel · **Posted:** Fri Sep 20, 2019 2:10 pm

Billybob wrote:

Yeah I agree that they seem to have the same PN

Keith may have been referring to a Gasser setup versus a CRD setup...I cannot find the post in question.

Is this the post you are referring to? Just as I suspected based on replacement part numbers, both year model alternators are internally regulated!
Still not sure why the 05 & 06 FSM's show different wiring diagrams between the two. But it would not be the first time we have found errors in the FSMs.
In this case, it looks like the 05 FSM's wiring diagram is correct and the 06 manual may have the incorrect information. :banghead:

GreenDieselEngineering Post subject: Re: pulsating lights on my liberty Posted: Wed Dec 18, 2013 10:53 am wrote:

The 2005-6 KJ CRD in North America uses a self-regulated alternator. The ecm only sends a wake-up signal after start-up once the engine is running stable. The alternator will turn itself on above a certain rpm threshold...maybe around 1000-1500. The service manual most likely was not updated properly.
The voltage spikes could be from a failing regulator on the alternator. An oscilloscope would would be very helpful to root cause the source.

The original post:> viewtopic.php?p=815560#p815560

GordnadoCRD · **Posted:** Fri Sep 20, 2019 4:58 pm

It's not surprising that the field excitation of the voltage regulator would work on PWM.

Virtually every single control system signal for any monitored function of the KJ works on PWM.

flash7210 · **Posted:** Fri Sep 20, 2019 7:09 pm

GordnadoCRD wrote:

It's not surprising that the field excitation of the voltage regulator would work on PWM

It’s not surprising at all.
It’s just not how the alternator on the CRD engine works.

I also don’t think the alternator is causing the OP’s “hard to start” problem.

phum · **Posted:** Fri Sep 20, 2019 8:01 pm

the drama continues,
I get codes P0108 and P0105 as soon the key is turned on.
It starts but runs in limp mode.
so far I have replaced the MAP sensor and cleaned the MAF sensor.
removed ECU and checked wiring there.
removed fuel filter and checked wiring behind there
I found 2 wires on the MAF sensor had the insulation rubbed off, fixed now.
I have had the P0105 code diagnosed as per the instructions given in the manual shown in the link previously posted.
I cant find anything on the P0108 code in this manual.
I also cant find a wiring diagram for the MAP circuit can any one help?
Any suggestions gratefully accepted.

WWDiesel · **Posted:** Fri Sep 20, 2019 11:34 pm

The FSM has no wiring diagram for the MAP sensor. :banghead:

These are the DTC's for the MAP sensor:
P0105 - Manifold Absolute Pressure Sensor Circuit Insufficient Activity
P0106 - Manifold Absolute Pressure System Performance
P0107 - Manifold Absolute Pressure [MAP] Sensor Circuit Low Voltage
P0108 - Manifold Absolute Pressure [MAP] Sensor Circuit High Voltage
P0109 - Manifold Absolute Pressure Circuit Intermittent

Billybob · **Posted:** Sun Sep 22, 2019 6:34 am

WWDiesel wrote:

The FSM has no wiring diagram for the MAP sensor. :banghead:

These are the DTC's for the MAP sensor:
P0105 - Manifold Absolute Pressure Sensor Circuit Insufficient Activity
P0106 - Manifold Absolute Pressure System Performance
P0107 - Manifold Absolute Pressure [MAP] Sensor Circuit Low Voltage
P0108 - Manifold Absolute Pressure [MAP] Sensor Circuit High Voltage
P0109 - Manifold Absolute Pressure Circuit Intermittent

@WWDiesel thanks for finding that link to Keith's comments as regards 2005/6 alternator function.

I recently had code P0108 on my 2002 Export CRD.
Power was down and if I floored the throttle to 4,000 RPM the engine would cut out.
Started it up again and it would run but poorly.

My diagrams call my "MAP" Sensor as being the "Boost Pressure" Sensor...with 4 pins.

I ended up replacing the wire going to pin 2....intake air temperature... on this sensor (MAP) at both ends as with the sensor plug disconnected and connector #1 on the ECM pulled out I was getting a funny Ohms reading on this wire with respect to chassis/ground. In other words this wire was supposed to be floating in mid air yet I was getting a varying Ohms reading with respect to ground.

Power was now very good....could floor it with no problem but CEL light remained ON.
Ran it for a few days and suddenly the CEL cleared itself.

So maybe the 4 pin sensor on the 2006 Wiring diagram page 8W-30-22 for the 2006 CRD is actually what we call the "MAP" sensor!.....someone with a 2006 CRD needs to check the wire colors going to the MAP sensor to see if they match up with the leads on page 8W-30-22

TKB4 · **Posted:** Sun Sep 22, 2019 7:59 am

That is certainly a plausible explanation and strong possibility. Great work Billybob hope it helps OP and maybe rest of us in future.

WWDiesel · **Posted:** Sun Sep 22, 2019 12:07 pm

Thanks Billy, looks like you found it. After looking at the 2006 FSM, it looks like it does indeed show the wiring diagram for the MAP sensor on 8W-30-22.
Went back and researched the 2005 FSM again for a similar 8W-30-22 diagram and it simply is not there.

NOTE: We are assuming that the 05 & 06 are wired the same in these areas. On the 05's, there is always the possibility that one or both of theses sensors wiring (signals/data) may still go through the Front Control Module which 06's do not have.

Billybob · **Posted:** Sun Sep 22, 2019 3:39 pm

@phum now that we have found the diagram for the MAP sensor you need to do the following as regards P0108.

With engine OFF check that Pin 1 on the MAP goes to GND.

The best way to measure these wires is to tape a pin/needle to the ends of both probes on your Multimeter.
This enables you to piece the insulation of the required wires to get to the copper inside...when you have fixed the problem seal up the small holes in the insulation with some glue.

Piece the Gray/Brown wire near pin #1 of the MAP and measure if this wire does go to ground.

With engine ON test that pin #3 Brown/Yellow has + 5 volts.
These two above measurements will probably show up as OK because your fault is intermittent.

You now have to measure these 4 wires from point to point for continuity.
Disconnect the battery and disconnect Connector #1 on the ECM and disconnect the connector on the MAP sensor.

Measure from end-to-end each of the above wires for continuity...the wiring diagram will show the layout of the pins in the Connector #1 at the ECM but you must check the wire colors at all times.
You should get good continuity end-to-end for each wire.
While you are doing the above check that none of these wires have any form of continuity to chassis/ground.
Once again these may show up as OK due to intermittent problem.

If you have no luck with the above...we should assume that this is an intermittent error ie. a wire rubs through to chassis when you go over a bump and the CEL gets set.
A bit drastic now but the next step is to replace the above 4 wires one at a time ie. cut the wire off at both ends a short distance from the connectors. Insulate the cut wire with tape at each end.

Now fit a new wire in place from the MAP to Connector #1 following the existing harness path. Solder the wires in place and insulate them at both ends.

Clear the Codes and test drive the Jeep to see if problem is gone.
Repeat the above for the other wires until hopefully problem is fixed then put the other wires back in place so that only the suspect wire is a new replacement.

Bear in mind that the CEL light will stay ON for a few days even if you have fixed the problem then it should go out by itself or else clear the codes if you are able to. Hopefully at some stage in the wire replacement procedure you will find that the Jeep now runs perfectly!

I was lucky in that while testing the wires with both connectors disconnected ie. wires should be floating in space I found one wire showing some slight continuity to chassis so I replaced that wire...Jeep suddenly had great power and CEL went out after a few days of driving.

Error code P0105 is sort of shown in the DTC index and refers mainly to the MAF sensor so you may have to do the same procedure as above this time with the MAF sensor...assuming this sensor is not faulty or has a bad connection.

The 2006 Jeep KJ Service Manual is a pain as regards the documentation.
Normally the index page has the DTC index right at the bottom of the page. You find your CEL code there and go to the page given and follow the procedure there. Code P0108 is not shown.

The "engine diesel" section starts at page 9-641 and at page 9-689 but does not cover all codes!

Have fun! :wink:

phum · **Posted:** Sun Sep 22, 2019 4:43 pm

Thanks so much, who would have beleived one get so much help from all around the globe.
Great forum, Great members,
Thanks again.

Billybob · **Posted:** Mon Sep 23, 2019 1:16 am

phum wrote:

Thanks so much, who would have beleived one get so much help from all around the globe.
Great forum, Great members,
Thanks again.

No problem...I am old and bored with too much time on my hands :wink:

This LOST site is the best but are you also a member of ausjeepoffroad.com?

That P0105 CEL....is that not being caused by the EGR delete that you have done?
My primitive 2002 2.5 CRD does not have things like MAF sensors or any sensors at all on the air filter box area! :wink:

phum · **Posted:** Tue Sep 24, 2019 4:48 pm

I wouldnt think so. the erg delete was done 2years, 20k kilometeres ago with no lights till recently

Billybob · **Posted:** Wed Sep 25, 2019 2:58 am

phum wrote:

I wouldnt think so. the erg delete was done 2years, 20k kilometeres ago with no lights till recently

P0105 code is shown in the DTC Index and can also be found from page 9-641 and 9-689...you may have to do similar wire testing as above but fixing one code may at the same time fix the other code as well.

phum · **Posted:** Thu Sep 26, 2019 3:00 am

Where can I get a diagram of the pin layout

TKB4 · **Posted:** Thu Sep 26, 2019 9:21 am

You can try here . Guess you need to look for boost pressure sensor on ecm.
http://www.colorado4wheel.com/manuals/Jeep/KJ/

hard to start

Who is online