2006 Ion odd electrical stuff and down shifting

[deguireb]

Hi,

This is a 2006 Ion with an automatic transmission. When shifted out of park and driven the interlock solenoid activates randomly when the brake is applied, power door locks also randomly relock when being driven. Transmission is good until things start clicking, then it stays in a low gear and revs high when trying to go 35mph. Resarting does not help most times.

I really thought it was a BCM issue and bought one at the junk yard today, did the 30 minute reset and was able to start the engine - had the same issue with the solenoid and locks activating.

I searched the internet for a while and could not find this issue mentioned with a solution.

Has anybody had this issue or have an idea of what to do next?

Service engine light has been off, it is now ON, this is due to the BCM swap.

Thanks, Bryan
Blackstone MA

[fdryer]

Since you assumed the bcm was the problem only to have it cine back with a replacement bcm, this may be related to main power (battery/alternator and power cables). Most vehicle electrical/electronic systems relies on alternator output regulated to around 14.5v for everything to run. Any issues that reduces this voltage can result in unusual problems.

1- don't guess. Try AutoZone or auto parts store offering free reading of error codes.

2- our cars, trucks and suvs use more electronics so the electrical system must be robust to handle it. Main power; battery, battery cables and their connections (red cable to engine fuse box and starter, two main grounds - battery to chassis and chassis to engine block. your trunk mounted battery relies on one long red cable from trunk to the Remote Start terminal next to the engine fuse panel. This extended stud allows for jump starting at the engine as the battery cable connects to it then distributes it to fuse panel and starter. Check for corrosion and loose connections.

3- how old is your battery? If in doubt, have it tested, free, at AutoZone or any auto parts store selling car batteries as most have testing equipment for in-store or in the car testing. Good batteries hold their charge and have 12.5v on standby. Dead or partially discharged ones will show less than 12.5v.

4- the alternator can be checked too. A tight drive belt will transfer engine power to spin the alternator. Normal output is at least 13.5v or higher with engine idling. Voltage below battery voltage suggests either a loose/worn drive belt tensioner or faulty alternator.

[deguireb]

Thanks for the reply. I reinstalled the original BCM and reset it, car is back to the way it has been, with the service engine light being OFF. It sat for a week before looking at it again. Battery was in the car when I bought it 2 years ago but seems to be okay, voltage measured 12.6V, with the car running 14.6V was measured at the battery. The charging system seems fine. Problem is still a mystery, any other suggestions would be greatly appriciated.

Bryan

[fdryer]

The park shift interlock and door locks are controlled by the bcm. Xmission shifts are controlled by the pcm. While all electrical connections are designed against long term weathering effects, corrosion can occur to create unusual problems and may be contributing to this problem.

After converting my 18 yr old L300 low beam projector lights from factory halogens to hids several years ago, the electrical connectors are well worn from disconnecting/connecting many times (lighting upgrade, lens polishing, etc). This led to frequently disabling the right or left light whether in drl mode or night driving. I homed in on the main connectors, spraying contact cleaner and spritzing with WD40 on male and female terminals. I'm hopeful the WD40 corrects the corrosion issue.

If you use remotes, maybe intermittent contacts are being made without touching buttons, creating the issue of door locks cycling? Maybe confusing the bcm since remotes communicate to the bcm. My new remotes tends to open my trunk at the slightest touch when putting it in my pocket.

Perhaps searching other Ion forums may help. Most GM vehicles use Passlock and Passkey for anti theft protection. Most are trouble free but there are issues with them. I don't think your Passlock remote use is the problem but reviewing its function and owner issues may help to at least rule out out.

[deguireb]

Looks like the problem was a bad contact. Last week I disconnected the three large connectors in the engine compartment and sprayed both sides with electrical contact cleaner. I also disconnected the drivers side door power window switches. It ran good for the past week then reconnected the window switches today and still ran good. Hoping this is the end of this problem.

[dcjredline]

Id start suspecting the micro switch in the shifter if the problem continues