On The Road / Help With Error Code

[1coyote]

Can anyone identify this error code:



P1652 - J1850 Short to Ground





Any help is appreciated.



1Coyote

 

[JApol]

for 05's maybe all 3rd gens
turn off the key and disconnect all ecm connectors.
read for 10 ohms or less from connector c2 pin 28 to battery negative
yes> next step
no> replace ecm

next, read from pin 28 to all other pins on both connectors, looking for more than 100k ohms
yes> refer to body diagnostic book, comms section.
no> repair wiring.
I'm going to try and find the what the body diag book is.

Section 9-1404 Dodge maint manual.

 

[1coyote]

Thatk you... This is an 04'

 

[JApol]

I didn't find anything worth anything about the body communications other than finding water leaks. I hope my previous post gets you going in the right direction.

 

[1coyote]

Any idea what part/system this is referring to?

 

[1coyote]

Anyone else have info?

 

[ReelDuel]

P1652 j1850 short to gnd

 

[Bob4x4]

A bus is shorted to ground,if this doesn’t make any sense to you maybe time to take it to a shop

 

[Prairie Dog]

Deleted - entered in error.

 

[cerberusiam]

Wiring harness scuffed or OBD port compromised. Do you have something plugged into the OBD port under the dash?

 

[ReelDuel]

No Sir nothing is plugged into the OBD port other than when I have my Smarty box plugged in to read the codes. Today truck started ok, none of the gauges,tack,speed were working, A/C not blowing cold, chk engine, fuel, Air bag, brake and ABS lights on. On the PRND21 gear selector you couldn't tell which position the shifter was in. The Info Cluster by the rearview mirror was powered but had blank data showing. About 8 miles later the gauges bounced on then off then a few miles later everything came on and was working normal. A/C started blowing cold also. I checked under the hood last night for any loose connections (none found). Reseated all fuses and relays (didn't find any corrosion) Batteries are 3 years old. Thank you folks for helping.

Wiring harness scuffed or OBD port compromised. Do you have something plugged into the OBD port under the dash?

 

[cerberusiam]

When it does that hook up the Smarty and see if the bus is down and the Smarty won't connect. IIRC, the cluster and OH console are all driven off the cluster controller and a bad connection or bad cluster will cause the observed problems but the bus will be live. If the bus is down it is probably the big grey connector on the firewall next to the brake master cylinder, could be it anyway on 1 or 2 wires.

 

[ReelDuel]

Cerber, I just hooked the smarty up and the "P1652 j1850 short to ground" returned from the drive into work I presume. So I cleared the DTC data. I'll check this again when I get home around 1700cdt. And will also check the big grey plug on the firewall. too.

 

[cerberusiam]

That means the bus is up and communicating. I want to say the J1850 is the 3 wire Cummins Weatherpac connector that is right there by the fuel filter. Check that harness and make sure one of the wires has not gotten bent, folded, spindled, or mutilated.

 

[MarkEagleUSA]

I want to say the J1850 is the 3 wire Cummins Weatherpac connector that is right there by the fuel filter.

The service manual says that J1850 is the PCI bus and references the Front Control Module.

 

[ReelDuel]

That means the bus is up and communicating. I want to say the J1850 is the 3 wire Cummins Weatherpac connector that is right there by the fuel filter. Check that harness and make sure one of the wires has not gotten bent, folded, spindled, or mutilated.

SO I came home checked the grey plug and all near it. Found a spot where the harness has been sliced open. I had a shop do some work about 6 mos ago and they ended up replacing some shorted relay to fix the fuel pump not getting power. Thus not getting fuel to start the truck. So they said. $500 later.
I just want to know why it just seems to be a cold start issue. Once it warms up it doesnt come back till the am the next day.

 

[PWong]

The service manual says that J1850 is the PCI bus and references the Front Control Module.

http://www.rambodybuilder.com/2005sbbgl/docs/wd/dr/wiringdiagrams/8w18buscommunications.pdf


Diagram 8W-18-5 and 8W-18-6.
The BUS is the communication circuit/wire between modules and ECM. So the BUS is the D25 circuit/wires that connect all the modules and ECM together through S230 and S195. Any short circuit in a wiring or a module will bring down the BUS.

 

[PWong]

So the D25 circuit is a piece of wire with multiple ends.
The short can be either on a branch of wire or a module. To check the integrity of D25 with a meter you need to unplug ALL modules at ALL ends. If there is no short in D25, then plug in one module at a time until you see the short.
If the short is intermittent then it hard to chase.

 

[cerberusiam]

Moisture, gets on any scuffed wire and creates a ground path. Warm the engine compartment up and it dries things out enough to stop the short and\or driving bounces the contact enough to break the circuit causing the problem.

Since the bus is not going down, just noting a problem, it isn't a constant dead short. Rubbed, sliced, bared wire is the usual source of that type of problem and it could literally be anywhere in the harness.

 

[ReelDuel]

Thanks for the responses. I didn't get to mess with it this AM but it did the same thing on the way to work. Then worked fine all day. Why does the A/C compressor not work when it does this? When things get warmed up the A/C gets cold again. I hate to send this to a shop to get fixed because you never know how long or how much it will cost.