1998 V70 AWD Flashing Arrow Question

[galexie64]

The Sticker on the ABS says RAMAC Industries, Inc.

[scot850]

OP says he tried wiping the messages and they come back immediately. Again, worth starting with the cable connectors being re-seated/cleaned and then we can work from there to test the ABS sensor resistance and checking the transmission speed sensor.

Also should look at the TCU connections as I have had an issue with corroded connectors giving spurious readings. Although that gave ABS/Engine check light warning lights.

Neil.

[galexie64]

Okay I will start with cleaning all the connections. One thing to note about this car is the PO lived on a muddy gravel road and the entire undercarriage had a thick layer of dried mud. I spent hours pressure washing the undercarriage.

[RickHaleParker]

43: AT-143. Kickdown switch, B5234T3, AW50-42

A4300526 Condition
The transmission control module (TCM) uses the kick-down switch signal to control functions such as downshifting during rapid acceleration. The kick-down switch closes when the outer sleeve of the accelerator cable is pressed against the switch (when the accelerator pedal (AP) is fully depressed). Diagnostic trouble code (DTC) AT-143 is posted if the transmission control module (TCM) registers a short-circuit to ground in the kick-down switch circuit when the throttle opening is less than 85%.
Caution! Diagnostic trouble code (DTC) AT-143 is posted when the kick-down switch is closed if the throttle position (TP) sensor signal is too low at wide open throttle (WOT) (less than 85%).

Substitute value
No substitution value

Possible source
Short-circuit to ground in signal cable
Defective kick-down switch
Faulty throttle position (TP) sensor signal
Transmission control module (TCM) replaced but throttle position (TP) sensor signal not adapted.

Fault symptom
No kick-down function.

----------------------------------------------------------------------------------------------
43: AT-232. Vehicle speed signal (VSS), AW50-42
Print

DTC information
en-US0800c8af80a1474f en-US0800c8af80a14802

A4300697 Condition
The vehicle speed signal (VSS) comes from a sensor on the transmission. The transmission control module (TCM) uses the signal to select the correct gear. The transmission control module (TCM) also uses the transmission speed sensor signal to determine vehicle speed. Diagnostic trouble code (DTC) AT-232 is posted if the transmission control module (TCM) registers that there is no vehicle speed signal (VSS) signal.

Substitute value
The transmission control module (TCM) "Emergency mode II" program is initiated.

Possible source
Open-circuit in the signal cable (+) or signal cable (-).
Signal cable (+) or signal cable (-) short-circuited to ground, supply voltage or each other.
Defective vehicle speed sensor (VSS)
Contact resistance in terminals


Fault symptom(s)
The combined instrument panel warning lamp flashes.
No lock-up function.
No adaption of the gear slippage times at high altitude (High Altitude Compensation)
No reduction of system pressure when shifting, making shifting harsher.
No reduction of system pressure when moving the gear selector between positions P-R, N-R and N-D which causes harsh gear meshing.
No torque limiting request to engine control module (ECM) when shifting

Note! The Motronic 4.4 engine control module (ECM) posts a diagnostic trouble code (DTC) when the transmission sends a malfunction indicator lamp (MIL) request. Erase this diagnostic trouble code (DTC) in the Motronic engine control module (ECM) when the transmission fault has been repaired.

[galexie64]

I will start by taking a look at the connections and wiring to the kickdown switch, VSS, and TCM. If that doesn't fix the problems, I'll try swapping the kickdown switch and VSS.

[RickHaleParker]

Pull the harness on the kickdown switch, Clear codes. Take out and punch to floor.
1. If the AT-143 does not come back, Kick down switch is welded closed or out of adjustment.
2. If AT-143 does comes back:

• A. short to ground in the kickdown harness.
  B. TPS is a lier.

[galexie64]

I will try that thanks.

I'm going to work on this Tomorrow afternoon. I will post the results.

[galexie64]

I ended up swapping the VSS from my parts car and the AT-232 didn't come back.
The AT-143 code seams to be a bad kickdown switch. I'm going to try swapping it too.

[zaneallen]

the kickdown switch is located on the firewall, and it isn’t replaceable without a whole new throttle cable, if the car is in sport mode it won’t matter if the kickdown is broken because the TCU only looks for the signal in Economy mode. But even in my case, when the kickdown switch was bad, it still downshifted to the lowest gear no matter what mode i was in (probably as a fail-safe)???

[RickHaleParker]

The Kickdown switch tend to break at the firewall mounding. See if you can pull it away from the firewall.