dozu

so based on the manual, after checking the sensor side connector, I am supposed to do the following -

Disconnect control unit connector.
2. Check resistance between control unit connector terminals.
Code No. 21 or 22 (Front RH wheel)
Terminals 10 and 25
Code No. 25 or 26 (Front LH wheel)
Terminals 8 and 23
Code No. 31 or 32 (Rear RH wheel)
Terminals 14 and 29
Code No. 35 or 36 (Rear LH wheel)
Terminals 12 and 27
Resistance: 0.8 - 1.85 kW

question is - How do I get to the control unit connector and the terminals ??!!

I located the actuator, but all I can see is this:


are the connectors/terminals under this cover? how do I open it?

thanks!!

kingrukus

iTrader: (41)

I still have to do this...

dozu

I wonna thank everybody for the help... I finally got rid of the ABS light.. it had code 35, left rear open circuit, so I replaced the sensor, then found out that it also added code 31, right rear.... replaced that as well, and all is good.

when I did the left side, I took the advice above, and busted out the sensor from the outside, and just pushed in the new sensor and it is now on 'friction fit'.

when I did the right side, I also took the rotor off, and give a good soak of WD-40 from BOTH the inside and the outside, and I hammered on the racket handle and the bolt came loose without breaking.

hope this helps to others.

kingrukus

iTrader: (41)

Guys, the FSM on BR-48 says to ground pin 8. why is everyone here saying pin 9?? And are you guys shorting it with another pin, or simply grounding it to the chassis of the ECM?

pmohr

iTrader: (26)

Ground pin 8, see what happens; it's a switched B+ feed. EC-642.

It says pin 8, but look at the diagram, pin 9 is labeled. Also check BR-44, the ABS control module connects to pin 9 on the DLC, not 8. Just a typo, the FSM is full of them.

Pins 4 and 5 on the DLC are ground, you can cross to those pins, or to any other ground source.

kingrukus

iTrader: (41)

I am a little confused. Am I supposed to be doing this to the pins on the OBDII port, or some other port? Is pin # 9 the top right pin, where the top is the wide side of the port?

pmohr

iTrader: (26)

The only diagnostic port you have is the OBD-II DLC. Yes, you short pin 9 on the DLC.

Right on BR-48, you have a pinout image.

kingrukus

iTrader: (41)

Thanks for your quick response. Turns out I have code #35.

This is awesome... the days of being able to diagnose cars for the shadetree mechanic are coming to an end.

kingrukus

iTrader: (41)

Has anyone managed to clear the ABS code following the FSM instructions? I cannot get mine cleared.

HOW TO ERASE SELF-DIAGNOSTIC RESULTS
(MALFUNCTION CODES)
NFBR0108S04
1. Disconnect the check terminal from ground (ABS warning lamp
will stay lit).
2. Within 12.5 seconds, ground the check terminal 3 times. Each
terminal ground must last more than 1 second. The ABS warning
lamp goes out after the erase operation has been completed.
3. Perform self-diagnosis again. Refer to BR-48. Only the start
code should appear, no malfunction codes.

UKmaxima

Wrong forum I know, but is the Quest/04+ Maxima ABS able to shoot out codes using this method? Looking at the Quest FSM, the ABS has a connection at Pin 7 of the OBDII connector. It is labelled K-Line which I believe is actually serial data. To test, grounding it will do no damage, but if anyone is scared, ground it with a 1K resistor to tst - this should pull it to ground but limit any current through the pin.

EDIT: It is the L-Line that is being grounded on pre 04 models. K and L lines are the old ISO comms standard. L is low line and is grounded to send data. Not sure it will work if the K line is grounded. It could be a typo in the fsm. I will try it tonight and report back.

Would be nice if all years gave up the codes so easy.

UKmaxima

You cannot get ABS codes by shorting pin 9 because it doesn't exist on 04+'s.

The wiring diagrams are a bit confusing for the 04 Quest. Both the ECM and the ABS ECU are shown to connect to pin 7 on the OBDII connector. If you look at the two areas of the FSM seperatly, you'd think that only either the ABS or the ECU depending on which section you were looking at, was connected to pin 7.


Now, what this does mean is that this is the main data K-line, and from my limited knowledge of ISO standards, this means that all ECU's in the vehicle are on this bus and all you have to do is send the correct Hex code for the address of each ECU. I believe if you know this address, you can do it manually in the "Enter Custom Code" area that most windows based diagnostics software has.

So if anyone wants to help on this, maybe someone with Cipher, if we can find the address of the ABS ECU, you will get data from it.

MrEous

iTrader: (11)

^^ Just an fyi...Cipher cannot read the ABS on a 6spd Maxima. I know this first-hand having owned a 2003 auto that did connect to ABS and now a 2003 6spd that won't connect.

I tried contacting Uprev about it and got a general answer that ABS isn't supported by Cipher for the 5th gen Maximas, at all. SMH, no help there

UKmaxima

Ok, thanks for the clarity.

The trouble is that a lot of ABS ECU's are NOT OBD compliant. Trying to find the ones that are is a task, and trying to find the protocols for the ones that aren't is damn near impossible for the average guy.

At the end of the day, unless its CAN or PWM, its just a version of the old serial stuff, but knowing what they did to it is the hard part. For instance the 5 baud init is not standard serial comms stuff.