CRD auto trans throws a fit - MIL was on P0733

GraemeT · **Posted:** Sat Sep 17, 2016 10:17 am

Hi all

2005 CRD 4x4 Auto - replaced ATF & filter 200 miles ago. Left parked up in 4L. Yesterday went to move it, started fine, lever into R and crawled backwards at idle. Hit a little bump and it stopped moving, gave it some revs and nothing - it acted like the transfer box was out of gear (i.e. engine revs up, no movement, no grinding, banging or other strange noises).

Sat in N for a minute or so, back into R and off we went. Onto the road, 15 miles to town in high 4x2 - no problems but did have the MIL on. Got to down ran a scan and had fault coded P0700 and P0731/P0730 (gear ratios incorrect) and a couple of others - like an idiot I cleared those down without recording them.

Restarted car P0700 came back along with the MIL.

No Limp Mode.

Left it for a bit, went back cleared P0700 and it has been fine since.

I have found a factory advice on some defective TCMs [url = http://webcache.googleusercontent.com/s ... clnk&gl=uk] here [/url] but mine falls outside of the dates mentioned there by three weeks.

[edit] Just been out and started her up then ran through the gears with foot on brake pedal - no MIL but scan tells me I have a 'Pending Fault' P0733 - Gear 3 Incorrect Ratio - Google has no suggestions that I can find other than maybe changing the input & output sensor - can anybody provide some other suggestions?

Graeme

papaindigo · **Posted:** Sat Sep 17, 2016 11:12 am

Shortly after fluid and filter change so I'd first look at:
1. level of fluid - dipstick is known to be a problem and the tranny likes more fluid than less. Add a qt or 2 of ATF +4 and see if problem goes away.
2. if not consider, I hate to say this, that a tranny filter has popped loose as that's been known to happen. Only way to check though is drop tranny pan.

GraemeT · **Posted:** Sat Sep 17, 2016 2:34 pm

papaindigo wrote:

Shortly after fluid and filter change so I'd first look at:
1. level of fluid - dipstick is known to be a problem and the tranny likes more fluid than less. Add a qt or 2 of ATF +4 and see if problem goes away.
2. if not consider, I hate to say this, that a tranny filter has popped loose as that's been known to happen. Only way to check though is drop tranny pan.

Hello - thanks for the prompt reply

1. I've had a look and it is way overfilled - it's a heck of a long way up the dipstick past the hot mark and that's at cold - not sure if too high a level could cause a problem but I can suck some out with the oil pump in any case

2. Well if I'm going to pump the ATF out then I may as well get most of it out and then drop the pan - shouldn't be to messy that way and I can save the fluid and reuse

I've ordered new sensors from the US so they'll be here at the end of the week - in the meantime I may also pull the existing ones and check/clean up the plugs and contacts.

Graeme

thefunk · **Posted:** Sun Sep 18, 2016 4:41 pm

Mine was acting up in a sporadic, strange way as well. Check the wiring harness that passes behind the alternator, between the alternator and the brace / mounting bracket. My brace had a casting defect that wore a hole into the harness and was shorting wires from the transmission. After I repaired the wires and ground off the rough casting I have not had a single fault. The transmission was never at fault.

GraemeT · **Posted:** Mon Sep 19, 2016 2:59 am

Thanks for the tip - I have just refitted the alternator after replacing the pulley on it so I may have pinched something there - I will check.
Googling has also suggested checking the Throttle Position Sensor and Crank Position Sensor as these interact with the TCM and, if faulty, will throw these codes whilst not throwing any codes of their own.

WWDiesel · **Posted:** Mon Sep 19, 2016 11:17 am

GraemeT wrote:

Thanks for the tip - I have just refitted the alternator after replacing the pulley on it so I may have pinched something there - I will check.
Googling has also suggested checking the Throttle Position Sensor and Crank Position Sensor as these interact with the TCM and, if faulty, will throw these codes whilst not throwing any codes of their own.

On the Jeep CRD, there is no Throttle Position Sensor on the engine, it is a drive by wire type with all throttle position control and feedback built into the foot petal mechanism...
fyi, If you are looking at the valve just below the intake manifold, it is called a Flow Control Valve and has nothing to do with throttle position... :wink:

GraemeT · **Posted:** Mon Sep 19, 2016 11:48 am

Hi - I was reading up on a Dodge that uses the same TCM and that was mentioned in the write up - one less thing to worry about then :-)

GraemeT · **Posted:** Thu Sep 22, 2016 1:32 pm

@papaindigo - may be a good call there, dropped the pan today and found that the 'neck' of the flat filter was no longer fixed in position so the back end of that filter had dropped. Currently waiting for the gasket to set (and for some more ATF +4 to be delivered) and will test it tomorrow.

@thefunk - I pulled that bracket and there is a sharp edge to the top, inner edge of the casting. This was highly polished where it is abrading the loom - on mine the outer wrap on the loom was a little frayed but no damage to the wires inside. Easy enough to just file the lip off the casting but that's not a brilliant bit of design - many thanks.

[edit] Just to confirm - done 250 miles now after reseating the pan filter with no problems/fault codes coming up - thanks

Graeme

CRD auto trans throws a fit - MIL was on P0733

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