P0891 Fault Auto Transmission 2.8 Crd

[dmbeale]

Hi

 

I have a 2006 Grand Voyager 2.8 CRD. EML came on and the auto box was unable to change into 4th gear (drives fine lower gears) Just revving higher and higher in 3rd. Managed to limp it home and not moved since. Plugged in OBDII and fault p0891 transmission fault appeared - relay circuit high or always on ????

 

Has anyone dealt with this before ?

 

Thank you in advance

[gordy]

As in relay circuit high it sounds like a sensor has lost its resistance and its went full circuit. Either that or a relay stuck in. Or how about an earthed wire between box and module, this has happened on numerous threads. Need to check back but more likely on tother forum. 

[gordy]

Well one of my two of my assumptions may be right. So what have wee. Now firstly the trans fluid must be at the correct level to start.

P0891 TCM power relay sensor circuit high.

P0891 Transmission Relay is always on..

This means Transmission Control Module senses there's more than 3.0 volts at transmission control relay output terminal of the TCM prior to the TCM energizing the transmission control relay.

Causes to this:

                       Intermittent problem with wiring and connectors.

                       Transmission control relay stuck closed.

                       Transmission control relay control circuit short to voltage.

                       Transmission control relay output circuit short to voltage.

                       Transmission control Module faulty.

So looking at about what have we first check, stuck relay and earthed wiring (heard these two before somewhere). If not maybe a Module..

[dmbeale]

Hi Gordy

 

Thanks for taking the time to reply - much appreciated. That's the direction I'm looking at first - transmission relay. I've also read that even an engine wash (guilty as charged) or driving in heavy rain could even affect if the TCM is exposed or under front left wheel arch. Are any of the 4 relays on the slam panel the transmission relay ?

Edited August 12, 2016 by dmbeale