• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Cat c 4.4

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
Hey guys I've got a cat telehandler here with a c4.4 and I suspect it needs a high pressure fuel pump. Iam a cummins truck tech so I bought the adaptor for my scan tool to hook up and I can only see the transmission module and no ecm. Is there another location for the data link connector other than in the fuse panel?

As well is the pump just your standard "lock the crank lock the cam lock the pump" repair? Looks fairly straight forward? I've done hundreds of pumps on the baby cummins just never really messed with the yellow stuff.
 

92U 3406

Senior Member
Joined
Jan 3, 2017
Messages
3,099
Location
Western Canuckistan
Occupation
Wrench Bender
I normally connected directly to the engine's plug. Should be your regular round 9 pin Deutsch located just under the fuel filters, hanging loose (if its a C series telehandler). On the D series machines its normally down by the batteries, on the plate with the master disconnect switch and DEF purge light.

What leads you to suspect pump failure?

Never done a pump on a C4.4 but Cat has some really out to lunch procedures for stuff on the smaller C series engines.
 

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
Engine serial number is TBY00485

It runs incredibly rough, low power every so often and when warm has a very hard start. Very little blow by, I've already bypassed the fuel tank and ran out of a jerry can and it still runs like a bag every so often. Replaced all filters and rubber lines.

With it being an electronic engine I was hoping I could hook up to the ECM but unfortunately only the transmission controller showed up.
 

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
I only have a snap-on HD scanner with the cat program and I bought the off-road equipment plug. that isn't a cat engine so maybe thats why the ecm dosnt show up?
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
28,977
Location
G..G..G..Granville.........!! Fetch your cloth.
TBY00485 is actually the machine Serial Number. Have a look on top of the valve cover for an engine Serial Number, or an engine arrangement. 313-1224 is the most likely Arrgt Number.
This is a Cat-badged JLG, so information is not as easy to come by as it would be otherwise.

According to the electrical schematic (attached, Page 10) the twisted pair of diagnostic cables takes signals from both the engine ECM and the transmission ECM. Those cables go all the way back to the diagnostic connector shown on Grid A-2 of Page 2.

With the correct scanner & software (Cat ET.?) it should be possible to read both engine and transmission ECMs.

If you need a Parts Manual you will find one in the link below.
https://csapps.jlg.com/CAGDocuments/MenuDocuments/D5258C1B-2F9D-4376-B9EA-AE9EC8D19B0031200369_H_TH336 TH337 TH406 TH407_CAT_Parts.pdf
 

Attachments

  • UENR7969-06.pdf
    970.1 KB · Views: 6

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
Ahh that makes sense. My cat program is through my snap on scanner and it only supports cat products. Anyway to get flash codes out of it? I work on all his dump trucks and concrete mixers so I took this on to try to help the guy out as the local cat dealer is weeks away to come out. Yay me lol
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
28,977
Location
G..G..G..Granville.........!! Fetch your cloth.
Unless you can get hold of someone who has Cat ET I'm not sure what other options there are. Maybe someone else can come up with a suggestion.

I've been around a number of machines like yours and have found ET to work on all of them - provided of course that the wiring to the Diagnostic connector was not damaged.

I've just been digging a bit more and found a parts listing for the engine. It is actually classed in the Cat system as an Industrial Engine rather than a Machine Engine.
 

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
Hmm well I guess I'll leave it in his ball court. Wait or roll the diagnostic dice. Like I say there is no smoke when running rough, no blow by and all the cylinders when using a heat gun are running within 40 degrees of each other.
Not an ideal situation I hate operating like this. I've invested 25 grand in various scan tools and every week I find another diagnostic tool I could use.
 

Jpsvenson

Member
Joined
Mar 28, 2021
Messages
18
Location
Ottawa ontario
Yea that's why I went the snap on route. Covers all class 8 on highway engines with full bidirectional control and service information.Still pretty expensive, but there's nothing it can't don't for on highway diesel engines just very limited on offroad. It wouldn't hook up to a 650h deere dozer so that was another service call I couldn't bill for.
 

92U 3406

Senior Member
Joined
Jan 3, 2017
Messages
3,099
Location
Western Canuckistan
Occupation
Wrench Bender
Are you plugging into the round 9 pin or the rectangular 4 pin connector? That 4 pin under the dash or in the fuse panel talks only to the JLG side of the machine. You've got to plug directly into the 9 pin round connector on the engine in order to see the engine ECM.
 

92U 3406

Senior Member
Joined
Jan 3, 2017
Messages
3,099
Location
Western Canuckistan
Occupation
Wrench Bender
Ok. That 4 pin flat connector normally reads the JLG side with the JLG Analyzer tool. Mainly for setting parameters and dealing with diagnostics for the controls.

There's no 9 pin connector on the engine itself? The TH series weren't overly popular out this way compared to the the TL models but I seem to recall they had a 2nd diagnostic plug on the engine like the TL models did. Some folks liked to plug the Product Link into the engine one.
 
Top