Hello everybody!

This is my first post so I think I should introduce myself. I'm Paul and I'm from Germany (so sorry if my english is not the very best). I'm a horse trainer and I own a 99 Dodge Ram 5.9 4x4. It's my daily driver and my work truck.
It's a nice car but there are some things to fix and now we've got some issues. I was dealing with a check engine light. There were some codes.
P0201
P0203
P0204
P0141
P0161
P0158

We changed all 4 O2 sensors. I already bought new injectors as well but I doubt that this will be the solution. Sadly after replacing the O2 Sensors the Check Engine light went on again. I reseted the PCM now. After 15 miles there is still NO check engine light. But after some miles the truck started to run very poorly....every time I hit the gas it seems like the truck is stalling. So I need a lot more gas than usual to drive. I never had problems like this before?!
The main reason why we started to work on the car is because of the poor gas mileage.(Around 9,5 mpg on gas and because the gas prices in Germany are extremly high (2€ / litre that should be around 2$ per 0,26 gallone....) the truck has a lpg installation...if you drive LPG you'll be at around 8,11mpg.) With all the codes and the mileage problem a problem with the o2 sensors seemed to be logical to me.

But the problem still remains and we haven't got any idea. Maybe there is an electrical problem? Do you guys have any idea? Hard to find someone in Germany who is used to dodge rams.

Thank you very much and sorry for my english again.

 

Willkommen beim Dodge Forum ! (Ich bin in Berlin aufgewachsen)

I'd think it's an electrical problem because most of the codes are "circuit" codes. The fuel injectors and the O2 sensor heaters get power from the auto shutdown relay. The PCM then grounds the other side to open the injectors or turn on the heaters. I believe if the PCM doesn't detect voltage coming in it sets a circuit code. I'd start my search with the ASD relay, wiring to/from it and also making sure the grounds at the PCM and engine are good.

 

Nothing wrong with your English or punctuation! I with a lot of other posters would be more like you.
P0201 Injector #1 Control Circuit
P0203 Injector #3 Control Circuit
P0204 Injector #4 Control Circuit
P0141 O2 Sensor 1/2 Heater Failure
P0161 2/2 O2 Sensor Heater Failure
P0158 2/2 O2 Sensor Shorted to Voltage

I would find the problem with P0158 that is probably the issue with 161 and 158. Look at the plugs and wires running to all the 02's there should be no melting of abrasion of the wires that could cause the short. Same goes for the injector wiring. You don't have a problem with mice chewing on wires do you? Also how did you clear the codes?

 

Ahh sehr schön! 100 km von hier!

I will check the ASD relay & grounds. Thank you! But if it's a problem with the ASD, why does the car still run? I thought it wouldn't even start?

Thank you very much!

We checked the wires and thought they look alright. I had no issues with mice or something like that. I cleaned the codes via OBD first. Then I resetted the PCM and the Check Engine Light was off for a while. Now it's on again.
I'm not really sure where I can go on. I think it seems like an electrical problem, right? But the transmission is shifting a little bit late as well and the gas consumption is just insane.

We checked the contacts of the PCM and found a resistance someone put in front of a transmission sensor. We removed it and the car shifted much later then. We put it back in and it shifted a little bit earlier again. But I think it's sill not the ideal. But why did someone solder a resistance in front of the PCM....seems strange to me? Maybe someone messed up the wiring?

There is another little problem I'm not sure about....you have to turn the key 2-3 times before starting the truck because of the fuel pump. If you try to start it on the first try the engine doesn't get enough gas. So I think that's a bad fuel pump but this couldn't be the reason for the codes and / or poor gas mileage or could there be a connection to the codes and the other problems?

Thank you very much!

 

Basically true except what if it's not a simple power/no power problem. E.g. the contacts in the relay are burned up and have high resistance causing a voltage drop. Similar with corrosion in connectors or wires. There is also one code 'sensor shorted to voltage' which possibly could affect the heater power (which also supplies injectors).
I think a good next step would be look at all O2 sensor voltages and the short term/long term fuel trims. This might yield some clues as to the bad MPG and if there are problems with the O2 sensors. What OBD tool do you have at hand ? My (certainly questionable) logic is that with so many circuit related codes something affects the power side of the components. You could try to measure voltage on the output side of the ASD relay but it might require a scope or similar to catch intermittent issues.

There are some changes with the transmission sensors over the years, maybe the resistor was added to somehow make the wrong part work. Might be good to know which exact pin the resistor was added.

 

If the asd wasn't working it wouldn't start/run. Check if the fuel pump is pressurizing the system with key on(one time) if not it's bad. You should see 49 psi as soon as you turn the key. You need to address the shorted heater(PO158) and you have 3 injectors not working. You need to check the wires from each injector(1,3 and 4) back to the pcm(Also check the power side). You can get noid lights and see if they are firing, Check the resistance of the three injectors in question. If everything checks out your problem is the pcm.

 

Okay so you think it's an eletrical problem and not a follow up thing because of bad injectors or something like that? (The injector thing is a bit tricky because of the LPG system installed I kinda have 2 injectors per cylinder but the Check Engine Light goes on in both modes. An explanation for this could be that you need to run on gas before you can change to LPG but a bad fuel injector wouldn't explain the high MPG on LPG....or maybe the LPG just need to be adjusted again and the real problem is with the fuel system?

I use a friend's scanner....think it's autel or something like that?

Because of the transmission sensor I have to take a look on which pin it was.

So I definitly have to turn the key 3 times before the engine starts when it's cold. But could this cause all the problems? Especially when driving in LPG the fuel pump isn't involved, right? So at least the bad MPG in LPG should have another cause?
But could the codes be thrown because of a bad fuel pump and is the fuel pump a reason for bad MPG?

So I try to find someone with a fuel pressure gauge and check the psi. Then I will check the resistance of the injectors and if they are firing. How do I check the power side of the PCM? If I check with a noid light it and it looks good, there is no problem with the wiring, right?

Do you think the 02 codes could be a follow up because of bad fuel pump or injectors? Or do you think it's a different problem and all the fault codes don't cause each other? I think I don't really understand this sentence: "You need to address the shorted heater(PO158) and you have 3 injectors not working." My bad school english....sorry

Thank you very much guys!

 

You have gas ans LP? Where are you located in Mexico? I don't believe they offer that in the US. And yes a shorted ground to the 02 heater can cause other fault codes with the 02's because they are not getting up to temperature fast enough. The heater helps the 02 get up to temp when it's cold. If it's cold the pcm wont revive accurate info. A noid light will flash when the injector would fire. But with the fault codes for the injectors i would think it's in the wiring or bad pcm. You need to check continuity with a meter from the pin on the pcm plug to the injector plug(all 3).

 

I have an LPG installation and you need fuel as well....so you have two tanks, two rails per bank, two injectors per cyinder and so on....I'm located in Germany. It's a pretty common thing over here at least for all the US cars because otherwise you couldn't afford the gas because of the high prices for e95 (gas). LPG is half as expensive as normal gas here.

Today I drove the truck and it started to lock and unlock itself while driving. So maybe it could be a problem with this aftermarket remote junk someone installed. I'm thinking about this junk could cause the problems? I will remove this and give it a try.
I will still check the injectors after all. I'll let you know if there's any changes.

Thank you!

 

Seems like it's the transmission temperature sensor. After resetting the PCM a few days ago it seems like the old codes didn't occur again but know it says P0711.
I hate electrical problems.... Why did someone put a resistor in front of that? Without the resistor the car shifts much too late....and I think it shifts a little late with the resistor as well....also there was too much oil inside the transmission....don't know if there's a connection or just a random fault.

Little bit annoying problems at the moment....