Menu
What's new
By:
Advanced search...

VSA fault Elimination

C

Channel Hopper

Members
Messages
1,683
Reaction score
262
Location
KT8 Postcode
Car
Accord 7 Estate 2005
Following on from this thread

http://typeaccord.co.uk/forum/topic/23411-wheel-sensors-my-experience-of-drilling-out/

which appears to have run its course since the ABS fault indication has been corrected.

WIthout going straight to 'swear a lot/buy replacement ABS modulator/scrape skin off appendages /swear even more', I hope at the vey least to identify which procedures will take the owner down a blind alley.

The faults that crop up on the instrument panel in paperclip mode are 6-6 on the ABS light and 3-7 on the engine light, the latter may be unconnected, though to verify I have a cheap OBD2 plug in unit arriving later today.

So far I have checked;
brake fluid levels and cleanliness in the reservior.
the brake pressure sensor for operation (but will double check the contacts again shortly),
the main connector to the ABS block for corrosion and bent pins
30 and 40A fuses in the main box under the bonnet, though I will be removing these in sequence later to see which warnings come up

There is a 'clunk' from the bonnet when the VSA switch is pressed when attempting neutralisation but so far I cannot identify from where, additionally I will look, dismantle and clean up the other electrical contacts that I can gain access to this morning , which includes the crank sensor, since it is mentioned within another thread that traction control plays a part.

I will take out the VSA switch later to check the contacts, I have no reason to think it is faulty as it does actively affect the number of times the exclamation mark light flashes during neutralising, however if it is a double pole throw and one contact is on the blink this may be behind the current scenario.

I have an MOT booked for lunchtime tomorrow but will speak to the station late this afternoon if there is no progress. they have often given verbal advisories on previous vehicles (mainly motorcycles) when they have been presented for testing, saving quite a few pennies in the past. I can check their unofficial stance on the warning light(s) before driving down tomorrow, with a view to not cancelling at the last minute.
 
Thanks, I'll pull out the switch in an hour.


The thread you linked suggests engine misfire fault was potentially behind the crank speed that was potentially behind the VSA lighting.

This engine light 3-7 that does not go away is definitely ABS only or possibly being interpreted by the car's brain as a misfire ?

And I still have to identify the whereabouts of the decreasing amount of power steering fluid, might a low level be part of the Honda logic to flag a VSA light ?
 
The thread was only for info on the 66 code, but I've just noticed you'd posted there anyway. As mentioned, code 66 is usually Un-Serviceable, but some people have got away with a re-balance procedure (ESM suggests several attempts, but this is for code 84, not 66).

The code 37 suggests an ABS solenoid fault. The Gauge Control module may be getting that info via the F-CAN from the VSA module (IIRC it's piggy-backed to the ABS board)

I think the misfire thing is potentially a red herring, whether petrol or diesel engine. It was ***ociated with VSA light flashing, not any particular code . A crank-sensor issue may be an internet misinterpretation of this (intermittent crank sensor fault ought to put engine into limp mode, and a DTC would be stored).
 
DTC 66:
VSA Pressure Sensor (Inside of VSA Modulator-Control Unit)

1. Clear the DTC using the HDS.
2. Test-drive the vehicle.
Does the ABS indicator come on, and is DTC 66 indicated?
YES - Replace the VSA modulator-control unit. ■
NO - The system is OK at this time.■


---------------------------------------------------------



DTC 84:
VSA Sensor Neutral Position

1. Check the DTC.
Is another DTC indicated?
YES - Do the appropriate troubleshooting for the DTC.■
NO - Go to Step 2 .
2. Do the VSA sensor neutral position memorization. [using HDS, but see below for paper-clip method]
3. Clear the DTC using the HDS.
4. Disconnect the HDS from 16P DLC.
5. Turn the ignition switch OFF, then turn it ON (II) again
Does the VSA indicator come on, and is DTC 84 indicated?
YES - Replace the VSA modulator-control unit. ■
NO - The system is OK at this time.■


---------------------------------------------------------

VSA Sensor Neutral Position Memorisation using paper-clip is mentioned here --> http://typeaccord.co.uk/forum/topic/23396-abs-vsa-fault-anybody-got-any-advice-please-cos-i-wanna-scream/page-2#entry242991
 
Thanks.

I managed to bag a pot of Honda PSF-S today from the dealer, filling up to the correct level has made no difference (but I was advised there is no sensor in the hydraulics so the first time people notice it normally is when the steering stiffens up).

Mechanic also said the fluid works its way through the rack to settle in the outer boots which is why I may not see where it has gone.
 
And speaking to the MOT tester a few minutes back, when I mentioned the VSA warning , he said as far as he's concerned it's not part of the MOT and I'll get an advisory at most.

I'll have a go with the OBD2 tester when it arrives, but I doubt I need to spend any more time/money, apart from about a fiver of overpriced fuel and a quick runaround beforehand.
 
Channel Hopper said:
And speaking to the MOT tester a few minutes back, when I mentioned the VSA warning , he said as far as he's concerned it's not part of the MOT and I'll get an advisory at most.
Click to expand...
Ask him when was the last time he went on a VOSA update course and give him the link to the gov website.
 
Don't poke the MOT tester with a stick.
Get your ticket and keep your head down.
 
I don't see how it can be listed as an advisory, as that would require having to identify it as a weakness against a specific MoT test requirement.
 
Jon_G said:
I don't see how it can be listed as an advisory, as that would require having to identify it as a weakness against a specific MoT test requirement.
Click to expand...
I'll advise him that the car doubles up as a hearse at weekends, I might knock up a coffin or two tomorrow morning to throw in the back.
 
I received the OBD2 scanner unit at 4pm today and have only just had time to download the app (Car Doctor something or other) and try her out.

It's a wifi only model but locks in perfectly with the Android phone, trouble is the app is only engine management it seems.

Two codes appeared P1248 and P2138 - throttle adjustment for the latter, not sure about the first .

Not sure how old they are but I cleared them and went out for a spin. After stopping and resetting the scanner no more engine codes have flagged up.

I will check after the MOT if the engine light code from the paperclip test has cleared and then go searching for an app that also takes the car's non engine bits into account, but for £16 delivered, it looks like a useful tool for the glove compartment.
 
It will only be able to read 'powertrain' (engine) codes whatever app you get... the hardware in OBD2 scanners does not interface with the other vehicle ECUs, although I did once find a Polish forum where members were exchanging posts on modding a commonly-available OBD2 scanner to read all ECUs. It was all a bit beyond me.

If you want to read non-powertrain codes then a cloned HDS is your best bet. Those will also run 'interactive' (target-setting) tests on the engine sub-systems, so very useful when problems occur.
 
OK, thanks for the heads up.

My engineer at the recovery company is Polish and will ask, he is pretty clued up on a lot of things I only dream about .
 
OBD2 is a US standard IIRC late-90's.

I think it was originally introduced for the "MOT" test in California, where they plug some kit into the OBD port during the test to check on certain engine parameters with (I think) the car on a rolling road. Since then it has spread to other states, not sure if it's nation-wide. But basically, to sell a car in the US, all engine ECU's since ~2000 have to have OBD2 connection. Note that this is how the VW "cheat" code worked, IIRC it was Bosch code for engines on test beds that VW used in the production release.

The 7th gen has its own proprietary CANbus into the other vehicle ECUs which is why you need HDS or a very expensive workshop generic scanner to read the other codes on a 7th gen. I think that a vehicle-wide spec for OBD came along about 10 years ago and the 8th gen conforms to that spec. AFAIK , if it's not possible now, it will at some point be possible to mix and match kit onto the CAN in a car. It's surprising how long this has taken, when I was at Rover 25 years ago there were a couple of people looking into global standards for a CAN system.

Most industries go the same way. In mobile networks, 1G (AMPS/TACS) was proprietary so if you started a network with say Motorola base stations, you were stuck with Motorola for the whole network. The 2G standards (GSM) were developed to overcome this issue, so in GSM you can mix base stations in areas of the network. Same applies to 3G (UMTS) and 4G (LTE).
 
The difference with canbus and earlier OBD2 was the takeoff points on the connector from memory. 2,4 10 and one other in the block, if the connector is fully wired it should be possible to inject access commands and to interpret what is returned.
 
At the time of the 7th gen some of the 16 pins on OBD2 can be used for proprietary comms with other units (and between the units). But the basic standard ~2000 was to get DTC's from the engine ECU (only) , in a clearly defined protocol that was not proprietary, using either an RS232 electrical derivative, or using a basic CAN electrical standard.

If there are other ECU's it's not standardized at the time of the 7th gen.

Note that the "blinking lights" and paper-clip method reverts back to the original OBD (aka OBD 1)
 
freddofrog said:
At the time of the 7th gen some of the 16 pins on OBD2 can be used for proprietary comms with other units (and between the units). But the basic standard ~2000 was to get DTC's from the engine ECU (only) , in a clearly defined protocol that was not proprietary, using either an RS232 electrical derivative, or using a basic CAN electrical standard.

If there are other ECU's it's not standardized at the time of the 7th gen.

Note that the "blinking lights" and paper-clip method reverts back to the original OBD (aka OBD 1)
Click to expand...
A picture tells a thousand words LOL

OBD2.jpg


--The red and grey are for power to the OBD reader (HDS or ELM327 or whatever)

--The green are for connecting to CANbus (no connection on the 7th gen)

--The yellow are K-line (pin 7) and L-line (pin 15) which are both RS232 derivatives.

--The blue are a Ford/GM protocol (no connection on the 7th gen)

You'll only find one of the systems on any car, ELM327 can communicate to the engine ECU using whichever is available.

On the 7th gen, HDS (or an ELM327) uses K-line. There is a K-line connection to the MICU (which acts as a proprietary gateway to CAN which HDS can read but some ELM327 cannot read). There is also a K-line connection to pin 23 on connector E of the engine ECU (not easy to find in the ESM) which is for direct reading of the engine ECU as provided for in the OBD2 standard (hence cheap generic readers can read the 7th gen engine ECU but nothing else).

As I've said, OBD2 was originally a standard of the protocols for getting DTCs from the engine ECU, whether it uses the yellow or the green or the blue physical/electronic connection.
 
RS232 is a protocol I know from gyro-stabilised communication platforms (and earlier with card emulators /dodgy ways of watching ITV Digital when encrypted in the SECA format).

The P2138 fault comes up as pdeal position incorrect voltage on one of the apps I grabbed with the Car Doctor one. The P1248 is linkes to this with an apparent two stage correlation error. Removing these with the OBD2 tool has coincided with the 3-7 disappearing from the dashboard though so I ***ume it was an old one that could not be cleared with the paperclip method.

Were/are the descriptions correct for the i-CTDI and the ABS link was a red herring ?
 
Channel Hopper said:
...The P2138 fault comes up as pdeal position incorrect voltage on one of the apps I grabbed with the Car Doctor one. The P1248 is linkes to this with an apparent two stage correlation error. Removing these with the OBD2 tool has coincided with the 3-7 disappearing from the dashboard though so I ***ume it was an old one that could not be cleared with the paperclip method.

Were/are the descriptions correct for the i-CTDI and the ABS link was a red herring ?
Click to expand...
You've correctly interpreted those diagnostic trouble codes, which do often appear as a pair, at least on our Hondas... http://typeaccord.co.uk/forum/topic/10469-just-got-p2138-and-p1248-faults/ ,but they could have been sitting there on your ECU for years waiting to be read/deleted?

I always did think that your engine light flashing was a red herring, at least in regard to your ABS problem(s). I've never heard of anyone reading engine fault codes that way on our 7th gen Accords, but you have raised an interesting issue... maybe, for clarity, it would be best to use an OBD2 scanner to delete off all engine fault codes before linking pins 4 & 9 on the diagnostic port to read ABS/VSA codes?
 
Channel Hopper said:
RS232 is a protocol I know from gyro-stabilised communication platforms (and earlier with card emulators /dodgy ways of watching ITV Digital when encrypted in the SECA format).
Click to expand...
I think that K-Line is basically similar in terms of baud-rate and the fact it's a 2-wire point-to-point link

Channel Hopper said:
The P2138 fault comes up as pdeal position incorrect voltage on one of the apps I grabbed with the Car Doctor one. The P1248 is linkes to this with an apparent two stage correlation error. Removing these with the OBD2 tool has coincided with the 3-7 disappearing from the dashboard though so I ***ume it was an old one that could not be cleared with the paperclip method.
Click to expand...
"P" codes are from an engine ECU, as defined in the OBD2 protocol standard. The ELM327 got those direct from the engine ECU over the K-Line link. AFAIK that particular paper-clip method does not connect to the engine ECU.


Channel Hopper said:
Were/are the descriptions correct for the i-CTDI and the ABS link was a red herring ?
Click to expand...
AFAIK a paper-clip method is based on backwards compatibility with the Honda OBD-1 (original OBD aka OBD-1 was proprietary). So that particular method probably reads from the MICU (which acts as gateway to the ABS/VSA)
 
Sidelined slightly by the euphoria of yesterday, I forgot to mention that when I looked in the fuse box next to the bonnet catch there are 33 fuse positions and these relate exactly to those in the owners manual, however fuses 32,31, 30 and 29 (all 7.5A) are not in the box at all despite them not being marked as optional accessory items.

Are these relevant in anyway to what is going on with the VSA light, no other part of the car seems to be on the blink by these not being installed.
 
Channel Hopper said:
Sidelined slightly by the euphoria of yesterday, I forgot to mention that when I looked in the fuse box next to the bonnet catch there are 33 fuse positions and these relate exactly to those in the owners manual, however fuses 32,31, 30 and 29 (all 7.5A) are not in the box at all despite them not being marked as optional accessory items.

Are these relevant in anyway to what is going on with the VSA light, no other part of the car seems to be on the blink by these not being installed.
Click to expand...
DO NOT put those fuses in, it powers up a system similar to ACARS that will send all your DTC's to VOSA and also lets VOSA know the car's location from the GPS antenna. If the car has recently been for an MOT, the VOSA computer then downloads FAIL THE CAR messages to all MOT stations within a 50 mile radius of the car.
 
freddofrog said:
DO NOT put those fuses in, it powers up a system similar to ACARS that will send all your DTC's to VOSA and also lets VOSA know the car's location from the GPS antenna. If the car has recently been for an MOT, the VOSA computer then downloads FAIL THE CAR messages to all MOT stations within a 50 mile radius of the car.
Click to expand...
:lol: :D :eek: Seriously made me laugh though
 
freddofrog said:
thread on code 66 started yesterday afternoon ---> http://typeaccord.co.uk/forum/topic/23455-vsa-warning-light/

VSA switch is 5-pin : pins 1 & 2 are a "push" contact , pins 3 & 4 are always connected , pin 5 N/C
Click to expand...
I forgot to mention that when I checked the VSA switch connections earlier in the week, whilst Pins 1 and 2 do make contact when pressed, Pins 3 and 4 are always no contact.

Should they be connected somewhere in the loom or within the switch ?

For clarification the two wires to Pins 3 / 4 behind the switch are Black/Red and Red respectively.


Additionally taking out the two VSA fuses bring up different codes (5-2 on the ABS light) and 18-4 on the engine light, the OBD 2 tool did say 'lost connection to the vehicle something or other'.

6-6 remains
 
Channel Hopper said:
I forgot to mention that when I checked the VSA switch connections earlier in the week, whilst Pins 1 and 2 do make contact when pressed, Pins 3 and 4 are always no contact.

Should they be connected somewhere in the loom or within the switch ?

For clarification the two wires to Pins 3 / 4 behind the switch are Black/Red and Red respectively.
Click to expand...
The ESM says (VSA OFF Switch Test)

Remove the VSA OFF switch from the switch panel

Disconnect the VSA OFF switch 5P connector

Check for continuity between the VSA OFF switch 5P connector terminal No. 1 and No. 2. There should be continuity when the switch is pressed, and no continuity when the switch is released.

Check for continuity between the VSA OFF switch 5P connector terminal No. 3 and No. 4. There should be continuity at all times

Channel Hopper said:
Additionally taking out the two VSA fuses bring up different codes (5-2 on the ABS light) and 18-4 on the engine light, the OBD 2 tool did say 'lost connection to the vehicle something or other'.
Click to expand...
I did say that the fuses also power the ABS ;)
 
You must log in or register to reply here.
Top