WH Glow plug module

[hotqld]

Any suggestions for further testing before I track down and replace the Glow plug module:
Current DTC P1648 Glow Plug module internal fault.

1/ I have measured resistance from the glow plug module plug to each glow plug all under 2 ohms.

2/While still unplugged I get 9.3 volts on each pin going to ea. glow plug with ignition on. Increasing to 10.4 volts when the motor is running. I find this interesting when glow plugs on the WH are meant to be 4.4 volts!!!!

3/Integrated Power module, swapped all relays around confirms the "auto shut down relay" is not faulty, circuit from there to glow plug module = good.

4/Ground terminal on the glow plug module is showing 2 ohms.???? bit high?

When the connection is plugged back into the glow plug control module = nil voltage at the glow plugs.


Code is generated from auto enginuity enhanced power train.
Manual says replace Glow Plug Module after checking for broken wires / fuses / relays.

The car starts faultless, The glow plug light on the dash is behaving normal I would not know the fault was there if I did not have a scanner that could get into the jeeps modules.

Anything else to test?

[DarwinDave]

Hi HOTQLD,
I had the same module error code come up on my WH a few months ago. I also had 5 glow plug errors as well. My mechanic confirmed that the module was faulty and may be affecting the glow plugs. The replacement cost for the module in Aus is about $600. As the car was still starting ok, albeit a bit slow on cold mornings, I decided to source a new module from the US. Through Ebay I got one from Huffines Chrysler in the States. It took 3 weeks to arrive and cost $236 which included about $57 postage. It also arrived in genuine Mercedes packaging.
When fitted the error code was cleared but I still had the 5 glow plug errors which kept re-appearing after each clearance.
I have just returned from a 8000km trip up to Darwin via Birdsville and the Plenty Hwy, all done with the 5 dodgy glow plugs. Since returning to Brisbane and the cold weather starting has been slow in the mornings so I have ordered 6 new glow plugs from the UK through ebay. I expect them to arrive, hopefully this week.
PS. I just made it back to Brisbane with the front drive shaft CV joint out of the transfer case totally stuffed. A common fault, it appears if the rubber protective boot has been split. (Possibly a legacy of going up and down "big Red" at the start of the Simpson Desert).

Hope this helps, Dave

[hotqld]

On the CV joint front drive shaft transfer case end, I replaced mine about 18 mths ago Caloundra radiator and CV joints....they charged about $230.00 I took the drive shaft to them. At the same time front diff mount under drivers seat was shot.

Thanks for the node on the glow plug control module seems a fairly regular fault, I am at $us160.00 and $us55.00 freight from RT autoparts...USA.

[Clarky]

I,m changing the same CV at the moment
http://www.ebay.com.au/itm/Prop-Shaf...#ht_2752wt_758

http://www.ausjeepoffroad.com/forum/...d.php?t=115627

The glow plug module video here
http://www.ausjeepoffroad.com/forum/...d.php?t=118475

[Doc]

Originally Posted by hotqld

Any suggestions for further testing before I track down and replace the Glow plug module:
Current DTC P1648 Glow Plug module internal fault.

1/ I have measured resistance from the glow plug module plug to each glow plug all under 2 ohms.

2/While still unplugged I get 9.3 volts on each pin going to ea. glow plug with ignition on. Increasing to 10.4 volts when the motor is running. I find this interesting when glow plugs on the WH are meant to be 4.4 volts!!!!

3/Integrated Power module, swapped all relays around confirms the "auto shut down relay" is not faulty, circuit from there to glow plug module = good.

4/Ground terminal on the glow plug module is showing 2 ohms.???? bit high?

When the connection is plugged back into the glow plug control module = nil voltage at the glow plugs.


Code is generated from auto enginuity enhanced power train.
Manual says replace Glow Plug Module after checking for broken wires / fuses / relays.

The car starts faultless, The glow plug light on the dash is behaving normal I would not know the fault was there if I did not have a scanner that could get into the jeeps modules.

Anything else to test?

Just wondering did you change your glow plugs and then the module or the module first

I bought 6 new glow plugs and they are ready to install

I have ordered a inspection camera first while the glow plugs are out I want to look inside the combustion chamber see what it looks like and after reading your post maybe I should replace the module as well at the same time

[hotqld]

Hi Doc
I replaced my Glow plugs 18 mths ago when codes like P0675 came up giving a DTC on the Glow plug circuit, the same as was on yours 2-3 months ago.

I would not replace the glow plug control module unless you have a DTC code P1648 that tells you to.

Having a bad day.....broke the fuel rail high pressure sensor and if that wasn't good enough then broke the crankcase breather valve......Oh well looks like 5-7 days on the motorbike now while parts come in from the USA....for at least the weather is good!