M915A4 won't start / no lights on trans box

Hello:

I searched and did not find the answer -> https://cse.google.com/cse?cx=partn...ers.com/forumdisplay.php?115-5-ton-and-up-TMs

Issue: Only a click when turning the key on. No action when the engine start key is pressed. All instrument panel lights, buzzer, and crash avoidance LEDs work.
Issue #2: Transmission box doesn't light up to be able to switch it into neutral

So far: batteries checked by a local (non-chain store) dealer - all are good - 25.63 volts using the end posts
All ATO fuses are good.
All ATO circuit breakers check continuity when pulled

Main goal: get the transmission into neutral so we can pull it out of the fire station

I have the 1500+ page manual.
m915_TM 9-2320-273-20.pdf
TM-9-2320-303-24P.pdf

VIN 1FVXAU0072PK01136
CONTRACT #: DAAE07-98- D-S001
ENGINE MODEL CUMMINGS NTC-400 BIG CAM
TRANS MODEL ALLISON AUTOMATIC HD-4560P

TIA

If the Allison controller does not light up, it will not permit the engine to crank. You will need to determine why no power is available to the controller, or, it is possible the controller has failed. The transmission should default to neutral when unpowered. If the truck won't roll, it is likely because compressed air is not available to release the spring parking brake.

The lever in chapter 6 of m915_TM 9-2320-273-20 looks completely different than ours. We have a pushbutton with D N R.

Are you referring to one of the controllers behind the seats mounted to the rear cab wall?

We have an air tap and keep the compressor (with oil and water filters) hooked up to it. The dash gauge shows 90psi.

You have an Allison "world" electronic transmission. The controller and keypad must be powered and functioning in order for engine cranking to be enabled. The lack of lit keypad is the clue as to why your engine won't crank. Check the keypad and controller (follow harness) for connectors that may have come loose.

Oh and that is not the right manual, you need TM9-2320-303-24-1 and -2. Download from JATonka website.

Is the transmission electronic only? Most transmissions will default into a specific forward gear as limp-home, if the selector is cable driven, but in this case it sounds not to be?

You could possibly jump the starter at the starter solenoid to get the engine running, but I am unsure what gear the transmission would be in, and therefore would only recommend it using a remote switch so nobody is standing by a wheel, in addition to filling the air tanks with air pressure ahead of time in order for the service brakes to work immediately and be held full on during cranking.

I would think an electronic selected trans is in neutral position anytime it is not powered, hence it can not energize any solenoids. The park brake should be what is holding the vehicle in place.

@74M35A2 - As I understand it, you are correct that the trans is in neutral unless it is told to do otherwise. Ours has the "mode" on it, also. It is electronic only and I cannot find a lever directly on the trans that would allow a "manual" maneuver.

Per TM9-2320-303-24P, I cannot find a fuse or fusible link at the battery. Might it be elsewhere? Should I ever worry about it since I am getting power to the instrument panel? The instrument panel is only 12v, however.

WP 0071 00 does not tell me which fuse but if it is a fuse in the center panel, I ran all the fuses and they are all good. I am wondering if there is a relay attached to the trans?




Next, unless told differently, I am going to take the plugs off the ECU and reconnect them. Maybe something will be knocked back into place.

@74M35A2 I believe it is in neutral when no power is applied. I cannot find a "manual lever" on/near the transmission to facilitate any specific gear. Yes, it is electronic only and ours has the mode button, also.

WP 0072 00 does not state which fuse is the VIM fuse. If it is located in the fuse block at the center of the dash, I ran all of those fuses and they were all good.

I cannot find a fuse or fusible link at the battery. Is this even worthy of chasing since I have power in the cab, albeit 12v?

Is there any way to determine if I have the "W65473 and below" or "W65474 and above" without climbing underneath?

I appreciate all of the great help so far! I am hoping to be able to pinpoint this issue the next trip.

@74M35A2 I believe it is in neutral when no power is applied. I cannot find a "manual lever" on/near the transmission to facilitate any specific gear. Yes, it is electronic only and ours has the mode button, also.


WP 0072 00 does not state which fuse is the VIM fuse. If it is located in the fuse block at the center of the dash, I ran all of those fuses and they were all good.


I cannot find a fuse or fusible link at the battery. Is this even worthy of chasing since I have power in the cab, albeit 12v?


Is there any way to determine if I have the "W65473 and below" or "W65474 and above" without climbing underneath?


I appreciate all of the great help so far! I am hoping to be able to pinpoint this issue the next trip.

Well since the truck is an A4 with a big cam and no electronics. Just screw the fuel knob in on the fuel shut off solenoid and jump the starter. It will fire.

The allison has to receive it's 12v to power the keypad up. Being that the dash and lights are all 12v then the power is getting to the cab. so I would suspect a bad keypad.

The VIM has fuses inside. VIM is Vehicle Interface Module, that is how the vehicle signals are made available to the transmission software. Some WTEC controllers are 24 volt, not sure about your A4, but I would think yes. So follow the work packages (WP) and you should be able to get to the bottom of your problem. Wes' is right about getting the 400 to crank up, but not much use if you can't get it in gear.

You also made a separate post here about the battery connections. Are you SURE all cables leading to vehicle loads are attached to the correct posts? If someone has been messing with these connections that was not trained (like a volunteer firefighter for example), it is quite possible things are not hooked up right. Double check using the proper TM.

Looking at your picture in the other post, there is a cable zip tied to the heavy +12 volt cable at battery post "1". The light gauge cable does not appear to have it's terminal connected to the battery lug. Smoking gun . . .

NDT said:

The VIM has fuses inside. VIM is Vehicle Interface Module, that is how the vehicle signals are made available to the transmission software. Some WTEC controllers are 24 volt, not sure about your A4, but I would think yes. So follow the work packages (WP) and you should be able to get to the bottom of your problem. Wes' is right about getting the 400 to crank up, but not much use if you can't get it in gear.

Click to expand...

I figured if he got it running maybe the WTEC has some feed power wire from the dual voltage alternator that it may get. Hard to tell on those trucks how they wired it in. It may get 12v from the alternator and the battery. Who knows

At least getting it started it will build air to move it from the shop

but I still did not find the VIM

NDT said:

You also made a separate post here about the battery connections. Are you SURE all cables leading to vehicle loads are attached to the correct posts? If someone has been messing with these connections that was not trained (like a volunteer firefighter for example), it is quite possible things are not hooked up right. Double check using the proper TM.

Click to expand...

I went and looked at a neighboring department's truck (same NSN), drew diagrams, took pictures and a video. It would have been fine had the firefighter made a diagram before pulling it out.

The only things I see beside post 1 are a battery rope and eyelet mount that goes around the bolt; however, you mentioning the zip tie made me look a little closer and I found the fuse. I have replaced the fuse and all is good to go... the tanker (tender) is back in service.

Thanks to all for your help and wise words!

NDT said:

Looking at your picture in the other post, there is a cable zip tied to the heavy +12 volt cable at battery post "1". The light gauge cable does not appear to have it's terminal connected to the battery lug. Smoking gun . . .

Click to expand...

Which picture were you referring to because I have the same issue with a M915A3?