Dead Allison MD3060 Transmission Shifter

[wheato22]

I recently had multiple occasions when my Monaco's MD3060 Allison transmission shifter console would not light up (turn on) and would not shift... completely dead. This occured the first thing in the morning. The engine would start but the transmission was out to breakfast.

I did the only thing I could think of which was to check the transmission fuse on the Front Run Box and the two fuses insidr the Vehicle Interface Module (VIM)... all three checked out OK. Voltages look great at 14.0v.

As the morning Sun warmed the coach and lunchtime passed I must have checked a zillion wires loosen'd and reseated all the connectors I could find the transmission shifter lights started to blink on and would stay on for a few seconds... the blink off. Oh... did I mention we were at 7500 foot altitude? Finally at about 3pm the transmission came to life and we drove 80 miles to Reno, NV for repairs... and eventually a rebuilt transmission TCU/ECU as Allison calls it.

Just now I discovered the following link RV Shifters.com

The have some neat suggestions that now appear to point out that thermal heating of the ECU sometimes fixes this problem. I quote from their website.
"Common problems we fix: Shifter display will blink few times or is out, especially when ambient temperature is cold. If this happens, try to read diagnostic codes from your ECU when display is ON. If you see code 69-32, problem is ECU [transmission computer]. Often with this code you will read additional codes like 22-16 [faulty output speed sensor or connection], 22-14 [faulty engine speed sensor], 21-12 [faulty throttle position sensor], 23-12 [faulty primary shift selector link]. But in reality you most likely have no problem with sensor or link fault. Those additional codes can be misleading.

How to read ECU diagnostic Codes:
Turn on ignition and press the Up and Down arrow keys at the SAME TIME for one second, then release. Your shifter should display that it is in Diagnostic Mode 1 as seen on the left. [d-1] following 4 digit code. If you see O-L [oil reading], press arrows one more time. To read additional codes press MODE button momentarily. The ECU can store up to five codes [d-5]. If you see 2 dashes, there are no stored codes in the ECU.

"Things to try when all else fails.
[Dead ECU - No display, Vehicle won't start].
Its been noted that warming the ECU can sometimes help. Heating the ECU with hair dryer for several minutes can occasionally bring the unit back to life. If it works, you will be also able read diagnostic codes, and ECU's self-heating may keep you going until the vehicle is switched off and cools again."

As a retired IBM computer nerd I recall searching for and finding intermittent main frame computer thermal issues many times...

The old hair dryer fix escaped me for sure...

[94-Newmar]

John at Transmission Instruments rebuilds your unit entirely and very reasonably. I've had mine rebuilt by him too.

Transmission Instruments

[HarveyP]

I agree. John fixed mine after a local guy charged me $$$ and left it worse than before. Save yourself the trouble and start with the man you will eventually go to for the cure. 100% satisfied. Good Luck, HarveyP

[Gizzard]

Last year finished the double drain and fill with synthetic tranny oil. The Allison has not been the same since. When coming to a stop the trans will downshift into first gear with a sharp clunk that nearly sends you through the windscreen. In addition the torque converter lockup, sixth gear, can only be reached using the mode c button to manually shift. At this point wish I had stayed with the Dexron II it was using. Any suggestions?
Gary, 1994 Vectra 35 with a sweet 5.9 cummins.

[wheato22]

Does not make a lot of sense thats it's the fluid. Have you taken a look at any fault codes that are saved. The Allison tech that helped me pointed out that normal wear in the throttle linkage to the Throttle Position Sensor (TPS) will cause TPS High and TPS Low errors. Those errors will cause shifting problems. In my case I found that the connectors in the ECU needed to be fully seated to clear a TPS High error in my 1994 Monaco.... Here is a Link that discusses the TPS assembly.
~~~~~School Bus Mechanic: Allison Automatic Transmission Troubleshooting MD 3060 Code 2116

[Elictrix]

Suggest that you get an Allison shop to Reset Fast Adaptive, and check your throttle calibration.
Changing oils won't prevent the transmission going into 6th gear. You have another problem here, eg engine fuel lever not going to full fuel position.

[rwinslow]

Check your 5.9 engine throttle lever and linkage. Any looseness in the linkage mechanism can make the TPS believe that it is not seeing full fuel position. The looseness builds over time but it will reaching a threshold point on the TPS that results in the problem you have noted - seemingly over-night. There have been several Cummins upgrades to the throttle lever, etc. on the 5.9 / 8.3 family of mechanical engines.

[HarveyP]

John at TransmissionInstruments.com just helped me out again. His website now has a troubleshooting section with very good instructions for checking proper power supply to the ecu. He is the man who rebuilt my unit after it began the "no start without first using a heat gun to warm up the electronics" problem. It has been flawless ever since, until two days ago. After reading his troubleshooting, I discovered it was a problem in the fused wire from the battery. Connectors get old and corroded, and not enough power flows. John guided me through this repair, and we are excited to be hitting the road again soon. Thanks to a man who provides quality to his customers. HarveyP

[WRENCH18]

Originally Posted by wheato22

I recently had multiple occasions when my Monaco's MD3060 Allison transmission shifter console would not light up (turn on) and would not shift... completely dead. This occured the first thing in the morning. The engine would start but the transmission was out to breakfast.

I did the only thing I could think of which was to check the transmission fuse on the Front Run Box and the two fuses insidr the Vehicle Interface Module (VIM)... all three checked out OK. Voltages look great at 14.0v.

As the morning Sun warmed the coach and lunchtime passed I must have checked a zillion wires loosen'd and reseated all the connectors I could find the transmission shifter lights started to blink on and would stay on for a few seconds... the blink off. Oh... did I mention we were at 7500 foot altitude? Finally at about 3pm the transmission came to life and we drove 80 miles to Reno, NV for repairs... and eventually a rebuilt transmission TCU/ECU as Allison calls it.

Just now I discovered the following link RV Shifters.com

The have some neat suggestions that now appear to point out that thermal heating of the ECU sometimes fixes this problem. I quote from their website.
"Common problems we fix: Shifter display will blink few times or is out, especially when ambient temperature is cold. If this happens, try to read diagnostic codes from your ECU when display is ON. If you see code 69-32, problem is ECU [transmission computer]. Often with this code you will read additional codes like 22-16 [faulty output speed sensor or connection], 22-14 [faulty engine speed sensor], 21-12 [faulty throttle position sensor], 23-12 [faulty primary shift selector link]. But in reality you most likely have no problem with sensor or link fault. Those additional codes can be misleading.

How to read ECU diagnostic Codes:
Turn on ignition and press the Up and Down arrow keys at the SAME TIME for one second, then release. Your shifter should display that it is in Diagnostic Mode 1 as seen on the left. [d-1] following 4 digit code. If you see O-L [oil reading], press arrows one more time. To read additional codes press MODE button momentarily. The ECU can store up to five codes [d-5]. If you see 2 dashes, there are no stored codes in the ECU.

"Things to try when all else fails.
[Dead ECU - No display, Vehicle won't start].
Its been noted that warming the ECU can sometimes help. Heating the ECU with hair dryer for several minutes can occasionally bring the unit back to life. If it works, you will be also able read diagnostic codes, and ECU's self-heating may keep you going until the vehicle is switched off and cools again."

As a retired IBM computer nerd I recall searching for and finding intermittent main frame computer thermal issues many times...

The old hair dryer fix escaped me for sure...

Thats funny i had a TV(i was broke)that i fixed that way,every morning i heated it and it would work all day.Then i was robbed,dont think they figured that one out,lmao.