E4OD dead?

[JohnDeStef]

Just drivin' along and the truck loses it's forward drive, and just revs. So I coast to a stop and move the selector through the gears. Nothing but more revs in any gear, with only slight forward or reverse momentum. Threw it in 4low and found enough forward momentum to limp a mile to park it in a safe spot.

In park or neutral, it idled very rough. Occasionally in gear, the tranny would catch and want to lurch hard even if I didn't have my foot on the gas...

BTW, I'm driving a '93 4door Bronco w/ a 7.3L Banks turbo diesel, w/ trans command. Just had the tcase and rear end gone through.

Reading up on searches, I found replacing the tach sensor and adjusting the FIPL might be places to start. None of the searches turned up the 'sudden revs w/ no drive or reverse' problem I'm having...

Sounds also like I might have done more damage by driving/reving the truck after the problem started....

Advise or help please? Thank you!

 

[94f450sd]

first you should get the codes read from the PCM.the autozone code reader cannotdo this.you need to go to a repair or tranny shop that has the good scanner.

 

[Mr_Roboto]

You can use the $35 code puller that they have or had at Wal-Mart.

HOWEVER, lack of any forward or reverse drive is indicatave of transmission failure. Possibly the front pump.

Even with every bit of electronics disconnected, the E4OD / 4R100 will still have 2nd and reverse.

Quote: "Occasionally in gear, the tranny would catch and want to lurch hard even if I didn't have my foot on the gas..."

That was the Torque Converter Clutch (TCC) locking up. The usual cause is a leak in the front pump leaking pressure to the TCC engage circuit. People usually assume it is an electrical problem, however the TCC is hydraulically locked out in reverse, so if the trans does it in reverse it is definitely hydraulc and not electrical.

 

[JohnDeStef]

Just browsing the transbuilder.com website and I stumbled across this page...

At the bottom of the page, there's a copy of a wiring schematic for a '93 7.3L Econoline, diesel, E4OD. On that schematic... "A malfunctioning relay can cause 4th gear starts in E4OD. Check for corrosion at the relay connector." It's referred to as the 'EEC' relay.

This might explain my problem...!?! I have very slight forward/reverse motion when in gear. The more I rev, the more the truck creeps. Then occasionally it hits and I have brief uncontrolled acceleration.

My truck and it's repair info is at my shop. Tomorrow I'll use the scan tool and advise. Could anyone give me a heads up on where to look for the EEC?

 

[Mr_Roboto]

If that were the case, simply disconnecting the pass side connector would get you back to second gear.

 

[JohnDeStef]

I'll give it a try.

...passenger side connector.. is that on the side of the tranny or engine compartment? What's that connector look like?

Where is the referred to EEC relay?

 

[JohnDeStef]

Unplugged the connector from the passenger side of the tranny and fired up the truck. Nothin'... just the same problems I've been having.

If the EEC relay was out, and nothing else was wrong, technically I *should* have been rolling in second... correct?

Guess I'm back to shoppin tranny shops. Thanks Mr_Roboto and 94F450SD.