Volvo ec240b

[Mack4255]

I have a Volvo ec240blc that i really hope someone can help me out on . To try to make it short this is where I’m at.
1. Lost signal to EMC ( said on monitor)
2. In manual mode machine died ( few days later)
3. Dealer came out said the ECU and v-ECU was shot .
4. I replaced both with new ones
5. I replaced engine wire harness also cause they said it was in bad shape.
6 . It cranks in manual mode now , go to auto mode still says ( no signal to ECU )
7. Dealer came back out and said grid heater is shorted .
8 I replaced grid heater
9. Still no signal on monitor.
10. Dealer said to replace pre heat relay and the auto/manual switch .
11. Did that today with no change.
As long as I’m in manual mode it cranks and runs fine. Switch to auto mode and still runs fine with everything working but says no signal to ECU. The starter will only engage when turning key in manual mode. If I turn the key when in auto mode I only hear the relay in fuse box behind the cab clicking .
Also I have replaced the starter safety switch that located right above the starter.
I don’t want to run it with no signal to ECU because dealer said that was what got the ECU and vecu the first time.
Thanks for any help u can give.

 

[uffex]

Good day Mack
Do you know if the new ECU's have been programmed for your machine ?
If I have understood correctly the machine runs in manual mode that means the engine ECU is functioning correctly there appears to be a problem with the V-ECU - Display ECU. The machine will only crank in manual ?
Kind regards
Uffex

 

[Mack4255]

The ECU and vecu was said to be programmed when I bought them and replaced at the same time.
The starter will only spin if I have it in manual mode. It does fire off and run fine after cranking it over. If I turn the key before I switch to auto mode I get power to the display but nothing on the starter.
After it starts in manual mode I then switch it to auto mode and that’s when the no signal to ECU shows up on the monitor.

 

[uffex]

Good day Mack
I suggest we handle the issue in parts first lets clear up the cranking issue, this is devoid of the ECU problem. Preventing cranking is down to a relay - the relay is dependant on two signals 1/ that the alternator is not running this can be that a fault with the diodes in the alternator gives the wrong signal 2/ The control lock out must be in the raised position. From your description is sounds as if you have had some electrical disaster i.e.. welding - striking an electric cable - jump starting are all possible causes.
It appears that this problem has effected a number of the functions so please remove and clean all ground connections and refit those cables.
If you would prefer we make some illustrative information please drop me a line.
Keep smiling
Uffex

 

[uffex]

Found this one may be helpful see attached
KR
Uffex

 

[Mack4255]

The RE3301 relay in the start circuit you have sent . I just replaced that relay cause the dealer said it would be a good idea. It is a little differ from the diagram or maybe I’m not understanding it right. My relay has 2 bigger wires , One hot coming from the circuit breaker and the other big wire I believe heads to the grid heater itself . Ok now the plug has only 2 smaller wires . The one in diagram showed 4 wires in that plug. The 2 wires in my plug when key is on and I have it unplugged from relay I got 24 volts on one pin and 9 volts on the other pin which makes no sense to me. Could that 9 volts be my problem ? I want to say how thankful and grateful I am for you taking your time in helping with this . Thank you every much .

 

[uffex]

Hi Ken
Your description sounds like the battery relay not the one we are looking for please see attached. Looking at our records it seems you are not the only 240B guy to have some trouble I have attached also. If you are still in trouble finding the relay post a photo of the bank behind the battery we will mark it up for you.
Kind regards
Uffex

 

[uffex]

Good day Mack
May I clarify the original PDF file "the control lock out must be open for cranking" I have used the term "raised" and this is not appropriate, please except my appoliges if this was misleading.
Kind regards
Uffex

 

[Mack4255]

 

[Mack4255]

Is this the relay we talking about

 

[Mack4255]

 

[uffex]

Good day Mack
Your picts seem to resemble a "C" model more than a "B" I am a little confused the display looks as B but the electrics panel is that of a C. Can you please post a photo of the tag plate at the cabin corner boom side?
The information I have been following is that of the B must look to the C model
KR
Uffex

 

[uffex]

Hi Mack
Take a look at the attached - you mention that ECU have been replaced was that of the display changed ?
Kind regards
Uffex

 

[Mack4255]

 

[uffex]

Thanks Mack that makes this a bit of a challenge try to find out some more and come back to you.
KR
Uffex

 

[Mack4255]

When I first got this machine the display didn’t work at all so I bought a new one and it’s been fine since. Probably a year later I had to replace the v ECU . Now I just had to replace the ECU and vecu from what Volvo dealer said to start with with no signal to ECU showing on display. The first vecu I replaced lasted a few years.

 

[funwithfuel]

PM

 

[uffex]

Good day Mack
It would appear that your machine is in the period of transition from B to C series we are not aware that these machine existed certainly none found in Europe may be the other guys have some knowledge your side of the water, so please disregard the previous information.
However we have made some information based on the C series and checks to make. please see attached.
Kind regards
Uffex

 

[Mack4255]

I did make a jumper wire re3301 and went from 30-87 . With auto /manual in auto it started. It did seem to struggle a bit by crank over , stop , crank over more , stop , then cranked over and started until letting of the key. The auto /manual switch is new from Volvo last week.

 

[uffex]

Good day Mack
have you 24Volts on pin 1 of the Auto Manual switch?
KR
Uffex