Hey guys,

Took my CRD into the dealership today because the dash died. They're telling me the entire ECU/PCM needs replaced for a couple of reasons.

1) It controls some of the interior functions related to the dash
2) It has an open EGR Circuit Fault and this is the main one that's telling them that need to replace the ECU
3) It has a glow-plug fault
4) It has two transmission faults

These are the exact codes it's throwing. Can someone with more experience chime in here and help me out? I'm finding it hard to believe that just "replacing the ECU" is the right course of action here.

P0100
P1140
P0688
P0671
U0121
U0002

Code translation from my quick cheat sheet although you might want pull a copy of the 06 FSM from Sir Sam's NOOB site (05 FSM lacks codes) and double check the codes and see what the diagnostics are:
P0100 - MAF sensor - may just need cleaning, may have loose connection, may need replacing in that order
P1140 - problem with turbo vacuum reservoir solenoid - may be vacuum leak, may be bad solenoid which can be bypassed to check. Fix leak and/or replace bad solenoid as needed.
P0688 - auto shutdown sensor circuit issue
P0671 - bad glow plug #1 - can check voltage but if you have the OEM ceramics I'd just bit the bullet and drop in a set of 4 Etenoc1 7v steel plugs (http://www.dieselglowplug.com/gx3123-di ... kkhtcoiad0) cost ca. $150-175 and a mornings DIY project
U0121 - lost communication with anti-lock brake module
U0002 - CAN C bus off performance may relate to U0120

3 of those codes and any transmission codes would have nothing to do with an dash "death" nor would whatever code they think relates to an open EGR. If the EGR is in fact open the dealer reaction is to spend your $s to replace the EGR but the correct reaction is to get a GDE tune and maybe pull and clean the EGR after which you can forget the EGR even exists.

Stupid question - does the car run but the dash doesn't function? If so I'd start looking for why the dash has no power.

My initial reaction for the dash and the P0688/U0120/U0002 codes, although I'm absolutely no expert on modern auto electronics for computer systems, would be a chaffed wire (on an 06 I'd look in the bundle behind the fuel filter head) or possibly one or more dead relays.

Others can certainly weigh in and you might want to consider calling Keith at GDE for his thoughts.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

I'd contact Keith at Green Diesel before I'd trust the dealers word.

_________________
Dennis
Considering sound advice, invent your own solutions
CRD

FYI - 06's had the brake ESP pump mounted behind the fuel head - made things bump into the wiring harness
damages the wires - gets all kinds of weird codes

worth checking.

_________________
2005 CRD
stuff
Skeptic quod gratis asseritur, gratis negatur

I would not trust your dealers as far as you can throw them.

The ECU has very little to do with the cluster....the BCM does send it a "wake up" signal so you could check the connection to the BCM from the Cluster connection.

Check fuses 9, 34 and 13 in the Junction Block inside the cabin.

Also check that the cluster is grounded at G202 which is in the left kick panel.

And as stated above...if you have the 2006 CRD remove the fuel filter mounting bracket and have a good look in that area for frayed cables.

_________________
2002 Export CRD 2.5 Sport

Thanks for the feedback guys. When it comes to fabrication and heavy lifting I'm good. Electronics and other such items...not so good! Looks like I'm going to pick it up from the dealer and take it to a local Diesel Specialist I found. They're reading over this thread has them too believing it's not an ECU and that they need to look at other items.

I'll keep everyone posted! Once I get this sorted it's time to install the lift!

X2 on the possible chaffed wiring, had exact same problem with cluster going dead if not all glowing up... Limp mode would occur sometimes as well

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RIP 10/31/2012
Green Metallic 2006 CRD Limited
GDE Hot tune ~ Pre-F37 TCM ~ Transgo shift kit ~ MagnaFlow ~ Homemade Provent ~ OME 2" lift & Airlift ~ Samco ~ Euro TC ~ Lift pump ~ Nylon fan blade & Hayden clutch ~ Etc!

Typical shotgun response. Shoot first, aim later.

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'05 Liberty CRD B100, SEGR - SOLD

'01 Beetle TDi B100, EGR delete
'83 Mercedes 240D B100, no EGR

--- SEGR Builder ---

I'm with you on that .
I work in the IT field and to frequently the solution is "reboot." Problem goes away until it comes back.

Think about it, was the CEL on previously, some by design such as ORM or other understood/accepted anomaly? Something triggered these codes and they appear unrelated, in some cases, so I'd lean towards exposed/shorted wiring maybe even fuses. The old domino effect can trigger others, but the ECU is reporting reasonable codes i.e. they're explainable. So it really isn't a garbage in garbage out scenario. The real kicker is the dash going dark, check fuses and wiring

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JW
'06 CRD - stock