• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

AW4 does not shift - help me finish troubleshooting

Alright, so I went through the whole harness:

C3: 4.92V
C8: 12.61V
C9: (NSS?) 0.00V
C14: 0 ohm
C15: 16-150 ohms
C16: 0 ohms
D2: (TPS) .79V-3.76V
D14: battery V
D16: battery V

I checked the three solenoids at the harness at the firewall under the hood:
C14: 0 ohms
C15: 16-150 ohms
C16: 0 ohms

Can the NSS be bad enough to mess with the TCM, but not messed up enough to give any other symptoms?
 
bigalpha said:
Alright, so I went through the whole harness:

C3: 4.92V
C8: 12.61V
C9: (NSS?) 0.00V
C14: 0 ohm
C15: 16-150 ohms
C16: 0 ohms
D2: (TPS) .79V-3.76V
D14: battery V
D16: battery V

I checked the three solenoids at the harness at the firewall under the hood:
C14: 0 ohms
C15: 16-150 ohms
C16: 0 ohms

Can the NSS be bad enough to mess with the TCM, but not messed up enough to give any other symptoms?
Click to expand...
Well, I hope someone corrects me if I'm wrong....but if you get the readings that you do at the harness under the hood, you are bypassing all the other stuff and getting just the reading of the harness and solenoids.

Did you check C9 with the key on engine off? I think you did (no offence) as you have voltage at C8.

As for your question of the NSS....I would say it could, simply because your getting no voltage at C9 and the TCU does'nt know what gear it's in, so it's defaulting. But I honsetly don't know the correct answer to your question there.

I have been hoping some of the other "more knowledgeable" guys would chime in here.

I was fortunate that I had access to a SnapOn Scanner to help me with my problem.

I did need to clean mine as it had starting issues in P and N. With the scanner I could also tell which solenoids were working when the shiffter was operated.

Not many shops (other than srealerships) around here have the older scanning gadgits (mines a 88) or program modules (for the newer scanners) to help diagnose the oldies.
 
90xj06 said:
from what pins did you check c16 and c14 to? check them to a ground, pin b on the gray plug or d7 on the tcu.
Click to expand...
I'm thinking he's getting the same reading from in the cab and under the hood also.
I recall somewheres in this thread he was using D7 in the TCU plug.
 
B.RAIDER said:
I'm thinking he's getting the same reading from in the cab and under the hood also.
I recall somewheres in this thread he was using D7 in the TCU plug.
Click to expand...

Yeah. No matter of the NSS or Speed Sensor or TCU was bad, if C14-C16 are giving 0 ohms or 150 ohms, then either A)wiring is bad B)solenoids are bad. right?
 
check from the b terminal on the gray plug car side not transmission side and see what you get to the negative battery post. in ohms
 
when you checked the ohms where you checking the gray plug to the tcu plug? ans are those 0's actually 0's or infinity?

next check all the resistances from the gray connector. (on the side with out the clip. the transmission side) on all of these check from the b terminal.

check from b - e
b - f
b - g

and see what you come up with.

?? did you get the diagram i posted ??
 
Last edited:
with ohms you want no power to the circuit it will blow the meter. and i think he was checking from the tcu's connector to the gray connector under the hood.
 
B.RAIDER: Yes, I tested C9 with Ignition ON, engine OFF, tranny DRIVE, per the Shift Pointers document. Maybe I'll pull the NSS this weekend and clean it, just to be sure. Don't worry, I need all the help I can get. :D

90xj06: I'll test those connections tomorrow when there is daylight, hehe.

B.RAIDER: at first, i did have the ignition ON, but since have realized the err of my ways and have been subsequently checking the solenoids with the ignition OFF. I should clarify that, sorry.

If there's anything I don't make clear, please point it out ... it possible I had a brain fart :looser:
 
bigalpha said:
If there's anything I don't make clear, please point it out ... it possible I had a brain fart
Click to expand...
I had to do some back tracking when I was doing mine.
What was the result of C10 as per testing instructions? ..... you might have mentioed it somewheres and I missed it:speepin:.
This is from tne shift link:
QUOTE:
When the fuse and resistor pack are known to be good, battery voltage should be seen at D16. Terminal C10 should have battery voltage only when the brake is depressed. When the brake is released, C10 should drop to 0 volts. If battery voltage is not seen at either D16 or C10 and the fuse and resistor pack are known to be good, the ignition switch or the wire from the ignition switch is bad and will need to be re- paired.

Also:
QUOTE:
In the chart you will see an asterisk next to the neutral- switch and comfort-switch checks. If battery voltage is not seen as in- dicated in the chart on both sensors, check for a blown 7.5-amp #13 fuse in the main fuse panel.

I don't think you have to Power-Comfort switch but the other is curcial.
This could answer the NSS question you asked earlier.
 
B.RAIDER said:
I had to do some back tracking when I was doing mine.
What was the result of C10 as per testing instructions? ..... you might have mentioed it somewheres and I missed it:speepin:.

Also:
QUOTE:
In the chart you will see an asterisk next to the neutral- switch and comfort-switch checks. If battery voltage is not seen as in- dicated in the chart on both sensors, check for a blown 7.5-amp #13 fuse in the main fuse panel.

I don't think you have to Power-Comfort switch but the other is curcial.
This could answer the NSS question you asked earlier.
Click to expand...

C10 was battery voltage with brake depressed, 0V with brake OFF.
I have NO comfort switch.
I have checked fuses 3 times, and there are no fuses that are obviously blown :dunno:
I didn't check the Power/Comfort port on the TCU connector, as I don't have that manually selectable feature. Will it still alter voltage between batt/0V?

Tomorrow, I'm going to re-check all the TCU pins and the wiring harness at the firewall and re-post a comprehensive troubleshooting information block. This way, I know that I checked everything according to instructions, and check all the suggestions from everyone.

This way, I'll feel less retarded and i'll cover all my bases. Thanks again, for all the help even if I seem discombobulated. :wierd:
 
bigalpha said:
Well, the TPS reads a little low ~3.7V.
The Speed Sensor shows 0V.

I don't have any classic NSS symptoms.

**Actually, the Speed sensor shows the correct voltage, but it doesn't cycle because I can't rotate anything by hand while i'm testing. i assume it's good though.
Click to expand...

That's normal for the speed sensor. On the 1996 and before, it's a switch that closes once per revolution. If it's bad the tranny will stay in 1st gear as the trans computer thinks you're not moving. Later models it's a hall effect sensor similar to the CPS sensor and you'll see a/c spikes as it rotates.
 
lawsoncl said:
That's normal for the speed sensor. On the 1996 and before, it's a switch that closes once per revolution. If it's bad the tranny will stay in 1st gear as the trans computer thinks you're not moving. Later models it's a hall effect sensor similar to the CPS sensor and you'll see a/c spikes as it rotates.
Click to expand...

If the Speed Sensor goes bad, can you still change the tranny manually?
 
Alright, so I went through the harness again:

C3: 4.92
C8: 12.4
C9: 0.01 (key on-engine off, 'D', TCM plugged in)
C10: brake off: 0.01V
C10: brake on: 11.7V
C11: (comfort/power switch) 0.00V
C14: "OL"*
C15: 60-120 ohms. it was changing as I was looking at it
C16: "OL"*
D2: closed throttle/no gas: .8V
D2: open throttle/ gas pedal to the floor: 3.77V**

*OL: according to manual, this mean "overrange"
** this is reverse to what Shift Pointers (SP) says. SP says closed throttle: 4.5V; WOT: .5V


I checked the harness in the engine bay:

b to batt neg: "OL"
b to e : "OL"
b to f : "OL"
b to g: "OL"
e to batt neg: "OL"
f to batt neg: ~60-140 ohms. It was changing as I was looking at it
g to batt neg: "OL"


1. Could this be caused by a bad ground? I checked all the grounds in the engine bay and they all checked out. I tested this by connected batt pos to each ground. Each ground checked out at batt V.

2. C9 doesn't check out voltage wise, according to SP.

3. D2 is also out of whack. Both voltage-wise and throttle-wise.

I think this should cover all the things. Did I miss any suggestions? If I missed something, or screwed something up, please let me know as I am sometimes a tool, lol.
 
Overrage or OL means that the resistance is above what the meter can measure. That is an open circuit versus 0 ohms which means a short. I'm still thinking the wiring down by the tranny is munched or you somehow have 3 bad solenoids.

1. The tranny gets its ground through the engine block. Sounds like you already tested that.

2. Yeah, looking at the wiring schematic C9 shuold have voltage with the shifter in D. Probably just need to clean the NSS.

3. The TPS voltage is fine. The SP you're looking at was probably for the older non-HO engines which had the TPS voltages running in the reverse direction.

Sounds like time to visually inspect the wiring from that connector under the hood to the tranny for damage. Then time to pull the tranny pan and measure the solenoids directly.
 
You must log in or register to reply here.

Similar threads

J
AW4 Problem shifting first to second when hot
Replies
2
Views
1K
cruiser54
C
P
2K IDLE - Odd Shifting - TPS? (I know.. I know)
Replies
3
Views
2K
Unclewolverine
U
P
99 XJ Transmission Issues
Replies
17
Views
3K
lawsoncl
L
K
Dreaded crank and cam shaft sensor problems.
Replies
4
Views
2K
Tim_MN
Tim_MN
FernGreen
Aw4 Transmission Delayed Engagement
Replies
1
Views
1K
lawsoncl
L
Back
Top