Hello! I have a Volvo 855 T5 -94 equipped with an automatic transmission. I am trying to put out the Check Engine Light but with no success so far.

Engine : B5234T
Transmission : AW 50-42

I have read the fault codes in both the A1 port and the A2 port.

A1
111 (No fault)

A2
335 (Request for MIL lighting from TCM)
444 (Acceleration signal)

When I clear the codes the ECU (Port A2) shows 111, but after 5-10 seconds with the engine running they are back, as well as the Check Engine Light.

I have been searching high and low for answers regarding these codes, as they don't make any sense to me. When the ECU throws the code 335, I would assume that the TCM should also throw a code, am I right?

Regarding the other code, 444, I have a hard time trying to understand what I should be looking for. I live in the beloved country full of Volvos, Sweden, and the swedish lists of trouble codes states that 444 is "Accelerometer, signal is missing or faulty" while english lists state it as a acceleration signal. Which of these two options is the correct one, and where is this device located?

Regards, Mcollstam

 

DTC information 3–3–5
Condition
The TCM can request activation of the MIL lamp via a signal lead to the SFI control module. If the ECM registers a fault with the signal lead, DTC 3–3–5 is set. When the ignition is switched on, the ECM checks if the signal lead is short circuited to voltage supply (high signal). When the engine starts, the ECM checks if the signal lead is short circuited to ground (low signal).

Possible source
Signal too high:
-Signal lead short circuited to voltage supply.
Signal too low:
-Signal lead short circuited to ground.

Fault symptom(s)
None.

Troubleshooting:
Check the lead between ECM #B26 and TCM #B15 for signs of short circuiting to ground

 

DTC information 4–4–4
Condition
If the ECM senses that the direct–current signal from the acceleration sensor has changed its mean setting (2.5 V) to more than 3.5 V or less than 1.5 V, DTC 4–4–4 is set.

Possible source
Signal too high:
-Signal lead short circuited to voltage supply.
-Break in signal, ground or voltage lead.
-Voltage lead short circuited to ground.
-Contact resistance in connectors.
-Defective acceleration sensor.
Signal too low:
-Signal lead short circuited to ground.
-Defective acceleration sensor.

Fault symptom(s)
May result in misfiring DTCs when driving on bumpy roads.

The accelerometer is the potentiometer attached to the throttle body. I would change it as it is not a very expensive part. Or get one from the scrap yard and see if the error goes away.