G/box: 70 Auto: - Is the TCM the ECU and if so were can I get one ?

Gandalph · Aug 4th, 2009, 17:30

Hi,

I put a Sun snap on diagnostic on my 1998 C70 T5 GT (Key S44 for those that have one) and it gave me the fault code P1618 which translates to the TCM transmission Control Module

Can anyone please tell me

1. Is this the Transmission ECU ? as I believe it is
2. Were will I get one other than a main dealer ?
3. How much will it cost me ?

Thank you for your help

Chris_Rogers · Aug 4th, 2009, 18:05

Does this car have an electronic throttle?

Code P1618 does not mean the transmission ECU is faulty.

For a pre electronic throttle car it is:

Wiring fault between AW 50-42 (gearbox ecu) and Motronic 4.4 (engine ECU)

For a car with an ETM it means:

Fault code stored in the transmission ECU.

What is the problem with the car?

Gandalph · Aug 4th, 2009, 21:05

Thanks for replying

I am not sure if this 1998 car is electronic throttle I will find out.

The engine management light came on and stays on, at the same time the autogearbox fault light flashes, goes of after a time and comes back on.

At the same time the brake circuit and ABS fault lights come on and go off eventually, I lose the speedo and my mileage ie wiped, out it comes back now and again.

Strikes me as being serious

Thanks

Chris_Rogers · Aug 4th, 2009, 21:44

Sounds like a problem with the ABS ECU and/or a disruption to the CAN network if it's a later car.

The ABS ECU supplies vehicle speed information to all the other systems in the car so a failure will show the type of symptoms you have.

Gandalph · Aug 4th, 2009, 22:10

What I can't get my head around is the fact that

why would it just be the ABS ECU ? (is this what they call the ABS Module ?)

All the ECU's are separate so why would it just be the ABS ECU

The engine management light should be one fault, the brake and ABS light another fault and now the speedo and mileage another ???

Chris have you met these symptoms before ? if it was the ABS & TRACS light I would be more certain its the ABS ECU/Module

Thanks a lot

Chris_Rogers · Aug 5th, 2009, 06:45

The ABS module provides the vehicle speed signal to the other modules. If the signal is missing (because the ABS module is faultly) the there will be faults in the other modules.

I suggest you get fault codes read using Volvo diagnostic equipment OBDII diagnostics is not going to show the fault codes on the other modules and can be misleading.

Aug 4th, 2009, 17:30	#1
Gandalph New Member Last Online: Sep 24th, 2009 21:24 Join Date: Aug 2009 Location: Crewe	Is the TCM the ECU and if so were can I get one ? Hi, I put a Sun snap on diagnostic on my 1998 C70 T5 GT (Key S44 for those that have one) and it gave me the fault code P1618 which translates to the TCM transmission Control Module Can anyone please tell me 1. Is this the Transmission ECU ? as I believe it is 2. Were will I get one other than a main dealer ? 3. How much will it cost me ? Thank you for your help

Aug 4th, 2009, 21:05	#3
Gandalph New Member Last Online: Sep 24th, 2009 21:24 Join Date: Aug 2009 Location: Crewe	The problem is Thanks for replying I am not sure if this 1998 car is electronic throttle I will find out. The engine management light came on and stays on, at the same time the autogearbox fault light flashes, goes of after a time and comes back on. At the same time the brake circuit and ABS fault lights come on and go off eventually, I lose the speedo and my mileage ie wiped, out it comes back now and again. Strikes me as being serious Thanks

Aug 4th, 2009, 22:10	#5
Gandalph New Member Last Online: Sep 24th, 2009 21:24 Join Date: Aug 2009 Location: Crewe	Thanks Chris for the reply I will try that What I can't get my head around is the fact that why would it just be the ABS ECU ? (is this what they call the ABS Module ?) All the ECU's are separate so why would it just be the ABS ECU The engine management light should be one fault, the brake and ABS light another fault and now the speedo and mileage another ??? Chris have you met these symptoms before ? if it was the ABS & TRACS light I would be more certain its the ABS ECU/Module Thanks a lot Last edited by Gandalph; Aug 4th, 2009 at 22:29. Reason: Forgot to ask

Aug 4th, 2009, 18:05	#2
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	Does this car have an electronic throttle? Code P1618 does not mean the transmission ECU is faulty. For a pre electronic throttle car it is: Wiring fault between AW 50-42 (gearbox ecu) and Motronic 4.4 (engine ECU) For a car with an ETM it means: Fault code stored in the transmission ECU. What is the problem with the car?

Aug 4th, 2009, 21:44	#4
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	Sounds like a problem with the ABS ECU and/or a disruption to the CAN network if it's a later car. The ABS ECU supplies vehicle speed information to all the other systems in the car so a failure will show the type of symptoms you have.

Aug 5th, 2009, 06:45	#6
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	The ABS module provides the vehicle speed signal to the other modules. If the signal is missing (because the ABS module is faultly) the there will be faults in the other modules. I suggest you get fault codes read using Volvo diagnostic equipment OBDII diagnostics is not going to show the fault codes on the other modules and can be misleading.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)