Fix for TSB 228011: Long Cranking/Tach Jumping/Misfire DTC

Post by **boosted5cyl** » 04 Jan 2011, 12:46

I've looked around but I can find what the fix is for this. I believe it was a re-routing of the crank sensor cable, anyone got more specific info? I shielded my crank sensor cables with aluminum and it helped "a little" but I still get the tacho jumping when I crank the motor to start it.

Post by **boosted5cyl** » 04 Jan 2011, 12:57

OK read around some more (as one does). Looks like I needed to shield the power cable, not the crank position sensor cable(s). I'll try and do this tonight, take some pics and post back...

Post by **jimmy57** » 09 Jan 2011, 10:54

If the transmission was out soon before this problem started then the cable routing and shielding may not be the cause.
The face of block and bell housing of trans must be clean on their contact surfaces or the suppression afforded is not adequate.
The starter introduces an oscillating magnetic flux on the flywheel and the signal from crank sensor is disturbed when the faces don't have clean contact. It is not a grounding problem and external grounds do not address this.
The hole face of flywheel that crank sensor "reads" has to be concentric and transmission/engine removal has been the cause of many dented sensor rings on flywheel that cause erratic running and misfire. The sensor ring runout can be inspected with starter removed and turning engine over by front crankshaft nut.

Post by **boosted5cyl** » 10 Jan 2011, 10:21

It was just the cable routing. Although I do think the transmission was replaced by the P/O judging from some of the cable supports not being attached. I routed the cable around the outside of the PCV, covered it in aluminum and now the car starts on the button, every time! Something it never did before.

I'll post a pic of the routing for other's reference.

sureready12 · Post by **sureready12** » 13 Nov 2013, 15:24

Hey there guys, I've got a 99 Volvo C70, i'm having pretty much the same issue. What sensors/cables you covered with aluminum foil that stopped your eratic tach and the starter issue. My car just doesn't want to fire up correctly, it will crank, crank, crank, but it's not a smooth crank/i feel like it's getting interference.

Post by **boosted5cyl** » 18 Nov 2013, 22:10

I think your C70 might be a P80 platform? If that's the case, look for the B+ terminal repair guide. Start with that first.
In the end I removed the foil on the cables, for some reason my tacho only jumps in the cold but it starts right up regardless.

allan4187 · Post by **allan4187** » 13 Jan 2018, 16:56

boosted5cyl wrote: ↑10 Jan 2011, 10:21 It was just the cable routing. Although I do think the transmission was replaced by the P/O judging from some of the cable supports not being attached. I routed the cable around the outside of the PCV, covered it in aluminum and now the car starts on the button, every time! Something it never did before.

I'll post a pic of the routing for other's reference.

Did this end up being a long-term solution for you? I'm having the same problem....

Post by **mrbrian200** » 13 Jan 2018, 18:36

If you look at his profile he hasn't been active since '14. We may never know if that fixed it for good.

Post by **mrbrian200** » 13 Jan 2018, 21:06

I would use guitar shield tape (copper foil, conductive adhesive), then put the whole thing inside a bit of familiar automotive style conduit. Conduit because: should the foil touch the engine/transmission shielding is potentially defeated. For extra measure you might try connecting the shield to chassis via a wire soldered to the foil tape. Some can be soldered to.

I would have assumed the errant signal was being picked up by the sensor. Volvo thinks current is being induced in the wiring.

atraudes · Post by **atraudes** » 18 Feb 2018, 18:22

I wanted to pipe in and say that the Faraday cage idea didn't work for me. I've had the long crank/tach jumping issue since I bought the car just over a year ago. Running an extra ground to one of the starter bolts cut the crank time down significantly and stopped the occasional message in the cluster, but didn't totally resolve it. This weekend I wrapped the starter and alternator cable in copper tape/foil and grounded it, with no change in behavior. It was wrapped in electrical tape and then repacked into the plastic conduit like it was originally.

The behavior isn't a showstopper; just irritating so I may just wait until the transmission needs to be rebuilt.