Cold start problem help request

jrsavoie · **Posted:** Thu Nov 12, 2015 1:42 pm

Get a diesel heater like a Webatso.

They even make them with remote start. No plugging in. If I ever get money saved we will have one on at least one diesel

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

That's a great idea. I did order this: http://amzn.com/B00W5BN3WE and it should arrive today or tomorrow.

I'm hoping that it will work because I have been to 2 parts stores and neither one could pull codes from my Jeep and they tried different readers. All they got was 'link error'.

If I can get some readings out of it, I'll post back with my findings.

If it doesn't work, is it possible to pull the connector off of the computer and use a multimeter on the pins to check the sensors?

Brasher · **Joined:** Sat Mar 14, 2015 7:02 pm **Posts:** 80

dyneq wrote:

That's a great idea. I did order this: http://amzn.com/B00W5BN3WE and it should arrive today or tomorrow.

I'm hoping that it will work because I have been to 2 parts stores and neither one could pull codes from my Jeep and they tried different readers. All they got was 'link error'.

If I can get some readings out of it, I'll post back with my findings.

If it doesn't work, is it possible to pull the connector off of the computer and use a multimeter on the pins to check the sensors?

It should work, the Jeep uses ISO 9141 which is listed as one of the supported protocols.

mass-hole · **Posted:** Thu Nov 12, 2015 4:28 pm

Did you ever talk to GDE or get them to alter your glowplug tuning?

I just found out recently that my jeep has the 5V glow plugs but has been set to run as 7V based on what GDE told me. I have had one failure recently, but it went through all of last winter in New England with zero starting issues. Many days below 0. This morning my garage was below freezing and it started on 3 glow plugs pretty easily. I'm pretty sure my wife abused it too and didnt even wait for them to warm up, just turned the key and went for it.

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

OK, so after reading the service manual, I have learned that the ECM checks two sensors used when you turn the key to ON: engine coolant temperature
and ambient air temperature. Based on those inputs, it tells the glow plug module how long to stay on.

Since I am having the most trouble starting at high altitudes (about 9,000 ft and above), I don't have much faith that these sensors are where my problem lies. I'll still check them and replace if necessary.

The gas Libertys use a barometric pressure sensor to detect altitude and the ECM can compensate for the thinner air. I can't find anything similar to that for the CRD.

flash7210 · **Posted:** Fri Nov 13, 2015 8:54 am

dyneq wrote:

OK, so after reading the service manual, I have learned that the ECM checks two sensors used when you turn the key to ON: engine coolant temperature
and ambient air temperature. Based on those inputs, it tells the glow plug module how long to stay on.

Since I am having the most trouble starting at high altitudes (about 9,000 ft and above), I don't have much faith that these sensors are where my problem lies. I'll still check them and replace if necessary.

The gas Libertys use a barometric pressure sensor to detect altitude and the ECM can compensate for the thinner air. I can't find anything similar to that for the CRD.

The MAP sensor is a barometric pressure sensor and a intake temperature sensor.
The small sensor on the air filter box is the air inlet pressure sensor.
Some liberty models have a ambient temperature sensor somewhere in the front grill.
And I have heard that there is a ambient pressure sensor in the ECM but I cannot confirm that.

If you email GDE they should be able to give you a complete list of all the temp and pressure sensors.

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

Thanks for bringing this up. I can't really figure out whether or not the CRD uses barometric pressure or not by reading the service manual (only the gas section mentions it specifically) or which 'ambient air temperature' sensor the ECM actually uses. I took a look at the front of my radiator last night and couldn't find it. My jeep doesn't have any bells and whistles like outside air temp on the dash, so maybe I don't have that one?

As luck would have it, my OBD2 reader arrived yesterday. This morning when I went to leave for work, it was about 25 deg F outside. The jeep had been sitting overnight (about 15 hours). The ECM reported 51 deg F for the coolant and the ambient air temp was showing as 55 deg F.

As I drove in to work, I occasionally looked at the readings. Once the coolant temp gauge on the dash reached fully warmed, the ECM showed 168 F, which is lower than I expected (new t-stat last year, so I was expecting more like 180 fully warmed up).

The air temp went up to 65. Is that expected as it warms up? I was expecting the ambient to stay more stable based on outside temps.

Is it possible that the coolant was still 51 after sitting in my garage overnight? I'm thinking I should replace that. As far as the ambient air sensor, that's definitely wrong. However, I have no idea which sensor to replace.

flash7210 · **Posted:** Fri Nov 13, 2015 12:56 pm

dyneq wrote:

As I drove in to work, I occasionally looked at the readings. Once the coolant temp gauge on the dash reached fully warmed, the ECM showed 168 F, which is lower than I expected (new t-stat last year, so I was expecting more like 180 fully warmed up).

That is normal operating temperature with a factory replacement thermostat.

Quote:

The air temp went up to 65. Is that expected as it warms up? I was expecting the ambient to stay more stable based on outside temps.

Intake air temp is taken from the MAP sensor which is on the engine intake manifold.
As the engine warms up so will this temp reading.
Boosted intake air from the turbo will also increase this temperature.

Quote:

Is it possible that the coolant was still 51 after sitting in my garage overnight?

Yes, its possible.
Park your Jeep outside and it will be much closer to ambient temps.

mass-hole · **Posted:** Fri Nov 13, 2015 1:04 pm

The barometric pressure sensor that is used to adjust fueling/engine tuning is built into the ECM itself according to GDE. I dont believe that the ambient pressure sensor on the air box is used on the GDE tune, nor is the MAF sensor.

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

Thanks again. It's been a while since I've cleaned the MAP sensor, so I'll be doing that next since it sounds like the ambient air temp is coming from that? Is the 51 deg F I saw for that suspect at all? I know the temp in my garage was lower than that.

flash7210 · **Posted:** Fri Nov 13, 2015 1:25 pm

dyneq wrote:

Thanks again. It's been a while since I've cleaned the MAP sensor, so I'll be doing that next since it sounds like the ambient air temp is coming from that? Is the 51 deg F I saw for that suspect at all? I know the temp in my garage was lower than that.

When I use TorquePro, the only air temp sensor I can read is the Intake Air Temperature and that comes from the MAP sensor.
If you believe that your coolant temp sensor is giving the wrong reading, leave your Jeep parked outside all night and check it in the morning for comparison.

Brasher · **Joined:** Sat Mar 14, 2015 7:02 pm **Posts:** 80

According to page 8W-30-35 of the 2005 FSM (page 854 of the PDF), The Ambient Temperature Sensor is connected to the ECM via wiring connector C106. C106 is the same connector as the Headlamps.

Basically what I am saying is that the Ambient Temp Sensor located on the grill is what I assume the ECM reads. If you turn the car on without C106 connected, you will actually get a DTC for an Ambient Temperature Sensor malfunction.

And just to make a small correction toward mass-hole, the sensor on the airbox would actually be considered a dynamic pressure sensor (since the air flows at some velocity through the airbox while the engine is running). This would register a pressure less than atmospheric.

dyneq · **Joined:** Tue Feb 19, 2013 1:01 pm **Posts:** 22

Thank you both (from here on out, to save typing, coolant temp sensor = CTS and ambient temp sensor = ATS).

Unless I hear a good argument otherwise, I am going to trust the wiring diagram for the ATS location. Another reason I'm leaning that way: ambient temperature means outside, not in the engine like the MAP sensor is (right?).

Where is the grill ATS located exactly? Do I need to remove the fan housing in order to access it? I took a look through the outer (body) grill and down from above with the hood raised last night, but didn't see it. I'll look for a violet/orange wire next time.

I will park it outside for the next CTS test. Question: what should the coolant temp be with respect to the actual (non-ECM sensor) ambient temp? I'm guessing it won't be a direct correlation since it's a liquid and contains ethylene glycol. I guess I could also keep it simple and take off the cap and stick a thermometer in there.

apardo001 · **Posted:** Fri Nov 13, 2015 3:30 pm

this is what you're looking for, if I remember correctly pre-2006 CRDs may have the connector only (no sensor) and after 2006 all CRDs have the sensor.

CATCRD · **Posted:** Fri Nov 13, 2015 4:38 pm

My 2005 came with the sensor, but no EVIC. So maybe that year the sensor came with the premium BCM??? Cruise, foglights etc?

dgeist · **Posted:** Fri Nov 13, 2015 4:53 pm

CATCRD wrote:

My 2005 came with the sensor, but no EVIC. So maybe that year the sensor came with the premium BCM??? Cruise, foglights etc?

I thought it (the radiator-mount sensor) was used only by EVIC on gassers, but I could understand all CRDs being shipped with the sensor for reasons very much like are being discussed here.

Dan

Brasher · **Joined:** Sat Mar 14, 2015 7:02 pm **Posts:** 80

dyneq wrote:

Thank you both (from here on out, to save typing, coolant temp sensor = CTS and ambient temp sensor = ATS).

Unless I hear a good argument otherwise, I am going to trust the wiring diagram for the ATS location. Another reason I'm leaning that way: ambient temperature means outside, not in the engine like the MAP sensor is (right?).

Where is the grill ATS located exactly? Do I need to remove the fan housing in order to access it? I took a look through the outer (body) grill and down from above with the hood raised last night, but didn't see it. I'll look for a violet/orange wire next time.

I will park it outside for the next CTS test. Question: what should the coolant temp be with respect to the actual (non-ECM sensor) ambient temp? I'm guessing it won't be a direct correlation since it's a liquid and contains ethylene glycol. I guess I could also keep it simple and take off the cap and stick a thermometer in there.

You'll most likely need to remove the grill cover to see it. Be careful not to break the tabs.

rankom · **Posted:** Fri Nov 13, 2015 7:21 pm

I have identical problem with my kj , so i did replace ats ,part number 05149265-ab located behind grill, i don't think is the issue but wait till tomorrow , i just parker outside for test as well , I'm planing to drive it after new year , starts ok indoors, but behaves just like yours if left outside in the cold, last winter i had it plugged but I'm trying to pin point this problem as well ,

Yeti · **Posted:** Sat Nov 14, 2015 7:45 am

dyneq wrote:

OK, so after reading the service manual, I have learned that the ECM checks two sensors used when you turn the key to ON: engine coolant temperature
and ambient air temperature. Based on those inputs, it tells the glow plug module how long to stay on.

Since I am having the most trouble starting at high altitudes (about 9,000 ft and above), I don't have much faith that these sensors are where my problem lies. I'll still check them and replace if necessary.

The gas Libertys use a barometric pressure sensor to detect altitude and the ECM can compensate for the thinner air. I can't find anything similar to that for the CRD.

for what i have found , the water temp sensor decide the time of the GP's must stay on , and air temp sensor decide how many voltage must flow from the GCU , I'm not completly sure , but its seem there is a map in the ecu for the altitude for correct the GP's management.
the CRD have the barometric sensor in the ECU , one MAP in the air filter box ......vacuum reading ? and in the intake manifold , the last MAP have the IAT sensor in it and is what the ECU use for adjust all the engine parameter

Joe Romas · **Posted:** Sat Nov 14, 2015 10:23 am

I have a 06 CRD I bought new that now has 66k miles on it with the original GP's. :mrgreen:

I got the GDE Echo tune in June of 09 at 26k miles and the following fall/winter I noticed the longer cranking times

My CRD is garaged every night, this only occurs on the first start of the day when it's stone cold.

My garage is heated to around 40f so it's not a case of a really long cranking time just several seconds before firing :?:

My wife drives it now and this morning came back in after starting it to go shopping saying it was slow to start so I should charge the battery :BANANA:

It's 36f this morning and the garage heater is not on yet and that reminded me to return to LOST and see if others shared my experience.

I suspect the GDE tune is causing hard starting when cold.

Warp2Diesel has driven it and thinks GDE messed with or eliminated the pilot injections, not a good thing to mess with.

He thinks that because it sounds like a tuned Power Stroke.

Since the Eco tune when I got the "Euro TC" I went to GDE's "full torque tune" :JEEPIN:

I've been thinking of calling Keith and possibly getting their tuning box and a copy of the OEM tune to see if my long cranking times persist and if so possibly going to another non GDE tune I've heard about.

Columbus Oh is around 1132 feet above sea level so I don't think it's especially a high altitude thing.

Joe

Cold start problem help request

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