2002 c70 2.3 hard starting

lavellp7 · Post by **lavellp7** » 30 Apr 2019, 19:36

help with this screen.is there anything not correct on this

lavellp7 · Post by **lavellp7** » 14 May 2019, 18:40

car still no start.only code is ecm-720a i checked from immm #4 to ecm# 22 circuit is good also check antenna ring connection that good .i even put on the Stabilant 22A on the pins(didt work),can i buy new immobolizer from volvo and update with vida with my old key.

Post by **abscate** » 15 May 2019, 05:45

Not unless you have the full VIDA subscription from Volvo, which costs $1500.

The software you buy from people online wont work.

Post by **RickHaleParker** » 15 May 2019, 06:57

It starts sometimes. If the immobilizer was the cause it would never start.
ECM-720A is a communication problem, like a bad phone connection.
The physical construction and layout of a communication cable is critical.
The reason communication cables, Coaxial HDMI .. ect cost so much is because they precision engineered products.

Take it to a Automotive Electrical Specialist and have him redo the wiring to the immobilizer the correct way.

lavellp7 · Post by **lavellp7** » 17 Jun 2019, 18:20

well i left the immobilizer alone with the funny looking connector.got on ebay found a service center that repair ecu for 189.00 if it can be repair.after few day at repair center got a email (unit burned up circuit) and replacement is 450.00 total.paid for replacement And on saturday installed ecu put key in and it starts every time............................i hope it stay this way........................thanxz all for any info that was giving

lavellp7 · Post by **lavellp7** » 06 Nov 2022, 18:23

well 3 years go by and at 22000 miles the same issues is back with the same code 720a

Post by **scot850** » 06 Nov 2022, 18:51

Do you have more than one ignition key and fob? Have you tried both to see if the same thing happens?

Did you ever replace either the ignition switch electrical portion or the antenna ring?

I had a quick skim of the post and don't see any mention of either other than cleaning the connector on the antenna. The antenna rings to start to brake up so will cause a no read of the key chip. Remove the antenna and have a really close look around the inner diameter of it and look for hairline cracks. Pulling one from a junk car is worth try and swapping out. Doesn't matter if the plastic clip on it breaks off as the dash panel holds it in place.

The electrical portion of the ignition key also wears out but I think that is the less likely of the 2 issues.

Neil.

lavellp7 · Post by **lavellp7** » 06 Nov 2022, 19:06

hello scot850 ............. only have one key, got 3 immo ring from junkyard none worked
on tuedsy i pull out the dice and plug up to see what going on,,,,,,,,,, i hope its not the ecu again

2002 c70 2.3 hard starting

Re: 2002 c70 2.3 hard starting