Fix what no dealer has been able to fix! P0069/P0107
After visiting a Mercedes Benz dealer and two Chrysler dealers, we have not been able to isolate what is triggering P0107 & P0069 fault codes on my Grand Cherokee 3.0 Diesel. I'll send $$ to the person that helps me fix this!
My WK has 66,000 miles on it, and no mods. (I also own a Liberty CRD with all the mods, but the WK is stock.)
The truck goes into limp mode when it is fully warmed up and idle. If the RPM's are kept over 900 at a stop, it prevents the limp mode from kicking in. It seems to happen more often on hot days or when I put it into reverse after fully warmed up. Fuel economy around town has dropped off considerably (16 MPG) but on highway is still running around 22-24 MPG. (again, no GDE Tune).
I first replaced both the barometric pressure sensors and intake temperature sensor. (A 0061539928) before bringing to the dealerships. Air filter is new and clean and there are no obstructions from the intake to the turbo; there is no oil pooling above the swirl motor. Although we have not run a smoke test, we don't see any air leaks.
The dealership, having tested if we had a bad alternator, leaks etc, reprogrammed the Drive Control Module per factory. √ Checked the 02 sensor. They even called STAR for advice.
So... this leads me with a few next steps... of which I'm not sure how to diagnose. I'm a shade tree mechanic... one of those guys that has a lift in their garage... but this one baffles me!
a) There is a ground problem to one of the wires (the engine is super clean, I don't see any chafing on any wires, particularly near the battery)
b) The sensors are actually doing their job... but what does that mean?
c) installed wrong replacement sensor?
Thanks in advance. I really like my Jeeps! The Liberty CRD is the most versatile truck I've ever owned, and my Grand Cherokee pulls boats and trailers like a mule... but getting a limp mode just as you are pulling out of a boat ramp is so frustrating!
a) The parts I replaced
b) a picture of the temp sensor..... it is down below the hose (see middle red oval in next picture)
c) Picture of the engine bay showing the location of the parts that were replaced.
d) The Dreaded Limp mode
I'd be curious if anyone can teach me how to do these steps:
First, using a scan tool with the Key on and engine running, monitor the MAP sensor voltage. If it is reading less than .5 volts, turn engine off, unplug the MAP sensor and, using a DVOM (Digital Volt/Ohm Meter) check for 5Volts on the 5 Volt reference circuit. 1. If there is not 5 Volts on the reference circuit, then check for the reference voltage at the PCM connector. If it is present at the PCM connector but not the MAP connector, repair the open in the reference circuit between the PCM and MAP harness connector. If 5 Volt reference is NOT present at the PCM connector, check powers and grounds of PCM and repair/replace as needed. (NOTE: On Chrysler products, a shorted Crank sensor, Vehicle speed sensor or any other sensor that utilizes the 5 Volt reference from the PCM can short out the 5 Volt reference. To fix simply unplug each sensor one at a time until the 5 Volt reference reappears. The last sensor unplugged is the shorted sensor.) 2. If you have a 5 Volt reference at the MAP connector, jumper the 5 volt reference circuit to the signal circuit. Now check the MAP voltage on the scan tool. It should be 4.5 to 5 Volts. If it is, replace MAP sensor. If not, repair open/short in the signal circuit wiring and re-check. 3. If all appears okay, perform a wiggle test. Start engine and manipulate the harness, connector and tap on the MAP sensor. Note any changes in voltage or engine speed. Repair connector, harness, or sensor as needed. 4. If the wiggle test checks out, use a vacuum pump (or just use your lungs) to draw a vacuum on the MAP sensor vacuum port. As you add vacuum the voltage should decrease. With no vacuum, the MAP sensor should read approximately 4.5 volts. If there is no change in MAP sensor reading on the scan tool, replace MAP sensor.
I would not spray directly on the sensor or use brake cleaner. Get a large Ziploc type bag and some electronics alcohol cleaner and place the MAF and intake portion in with a good dose of alcohol. shake it for a bit to get the dirt out of the sensor and let it drain and dry.
I took the MAF out and it was like factory clean, but I did take the suggestion to clean it with alcohol. No luck there as I did get the limp mode late this afternoon in Atlanta traffic. I also took off the intake and it too was free of smudge and no more than a drop of oil in the turbo intake. Great suggestion as it seems you all are trying to rule out anything that may be constricting air.
I had not thought about the MAF before as the codes are related to the pressure sensor. Is the thinking there that if the MAF is reading off the ecu can't determine a good pressure differential?
I ordered replacement parts as suggested. Ouch on the price but still cheaper than a dealer visit. I had already replaced the MAP sensors, but I ordered new ones just the same. I'll post back with results when I get them in which may be two weeks.
Does anyone know how to check if the wires could be grounded? Getting the 5v? My OBDIi does not provide the values in freeze frame. I can post pictures of the connectors to the MAP sensors.
The items you ordered:
Qty Product # Price EA
1 SENSOR. MAP. 68066040AA $57.98
1 SENSOR. Right. Air Pressure, MAP, Pressure. 05101120AB $62.40
1 SENSOR. Mass Airflow. 53013673AA $97.94
Your order summary:
3 products, 3 items $ 218.32
Shipping To GA, USA $ 32.95
I got limp mode twice on my CRD. Let me ask a few questions, which may to totally off, but worth a try.
Have you checked your ECM/PCM lines running from the connection in front of the battery, back to the engine? When they run past your coolant lines (touching), they may super-heat the lines and cause a short circuit and cause issues. Tie them back
Have you checked your DPF in/out pressure lines? They run on opposite ends of your DPF. Trace them back to above your engine where they connect and see that all the connections are tight.
Sorry if this hasn't helped. I've been in your shoes before, with the amount of frustration. Hoping I could help in anyway.
2008 Jeep Grand Cherokee CRD
GDE Hot Tune, DPF Delete, Turbo Res. Delete, Exhaust Res. Delete