Auto transmission bad behaviour - Page 2

BigRuss · 12th November 2018, 09:20

It most likely won't be the ones the the Autobox ECU it's more likely to be the connectors in the engine bay, especially the one just above the gearbox where the Autobox loom connects to the main loom ;

Russ

LeRich · 12th November 2018, 21:09

Quote:

Originally Posted by BigRuss

It most likely won't be the ones the the Autobox ECU it's more likely to be the connectors in the engine bay, especially the one just above the gearbox where the Autobox loom connects to the main loom ;

Thanks. I think that connector is just beneath the airbox so should be easy to access.

Do you know if the auto ECU is coded to the car? It has a sticker with the VIN printed on it which makes me think it's not a generic part.

LeRich · 2nd December 2018, 20:54

Further update on this.

I sourced another transmission ECU and swapped them over. Initially the box behaved well but the old habits crept back. Original ECU seems not to blame so has been refitted.

Following Russ's suggestion, today I removed the battery and airbox to access the top of the gearbox and check the wiring connections. Unfastened the two connectors and both appear in good condition. What I have noticed however:

1. There is a small pipe on the top of the box (circled red below) that appears to receive a pipe, alas there is no pipe to be seen. There is some oily residue in the area - could this be from the pipe? And what is its purpose?

2. The main wiring connector has been wedged between the battery tray and gearbox, causing the marks circled green. The wire to pin 15 has been squashed but appears in tact (circled blue).

I tested the resistance between the pins as per the schedule below (c/o DMGRS). All were in spec apart from the pressure control solenoid (4.0 ohm), 2/4 duty solenoid (4.1 ohm) and TCC solenoid (14 ohm).

The solenoids are showing a little extra resistance but not significantly so. Any further ideas?

I have also replaced the upper engine mount at the same time for a good used item. The original was soft and starting to split. The 'new' one is much firmer; it was sold as from a 1.8 but the numbers cast into the rubber are different. It has made for thumpier gearchanges but I'm hopefully it'll keep the engine steadier.

trikey · 2nd December 2018, 20:57

Don't worry about the pipe on top of the gearbox, its a breather and doesn't have anything connected to it.

LeRich · 2nd December 2018, 21:11

Quote:

Originally Posted by trikey

Don't worry about the pipe on top of the gearbox, its a breather and doesn't have anything connected to it.

Phew! Thanks.

12th November 2018, 09:20	#11
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	It most likely won't be the ones the the Autobox ECU it's more likely to be the connectors in the engine bay, especially the one just above the gearbox where the Autobox loom connects to the main loom ; Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

2nd December 2018, 20:54	#13
LeRich Posted a thing or two Rover 75 Cont SE 1.8T Join Date: Aug 2010 Location: Cheshire Posts: 1,082 Thanks: 215 Thanked 232 Times in 178 Posts	Further update on this. I sourced another transmission ECU and swapped them over. Initially the box behaved well but the old habits crept back. Original ECU seems not to blame so has been refitted. Following Russ's suggestion, today I removed the battery and airbox to access the top of the gearbox and check the wiring connections. Unfastened the two connectors and both appear in good condition. What I have noticed however: 1. There is a small pipe on the top of the box (circled red below) that appears to receive a pipe, alas there is no pipe to be seen. There is some oily residue in the area - could this be from the pipe? And what is its purpose? 2. The main wiring connector has been wedged between the battery tray and gearbox, causing the marks circled green. The wire to pin 15 has been squashed but appears in tact (circled blue). I tested the resistance between the pins as per the schedule below (c/o DMGRS). All were in spec apart from the pressure control solenoid (4.0 ohm), 2/4 duty solenoid (4.1 ohm) and TCC solenoid (14 ohm). The solenoids are showing a little extra resistance but not significantly so. Any further ideas? I have also replaced the upper engine mount at the same time for a good used item. The original was soft and starting to split. The 'new' one is much firmer; it was sold as from a 1.8 but the numbers cast into the rubber are different. It has made for thumpier gearchanges but I'm hopefully it'll keep the engine steadier. __________________ Rover 75 1.8T Contemporary SE Auto Starlight Silver MBB Last edited by LeRich; 2nd December 2018 at 21:01..

2nd December 2018, 20:57	#14
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,765 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	Don't worry about the pipe on top of the gearbox, its a breather and doesn't have anything connected to it. __________________ Lest we forget..