Hi, the technician is correct about the info. ABS specs has a speed sensor on every wheel. This sensor is what tells the ABS control module about an imminent wheel lock, and from this info the ABS regulates the braking pressure so the wheel do not lock. This speed sensor can also send the same speed reading to the combinations meter which your speedometer is read on the screen. Also this same info goes to the ECM and then knows the road speed.
P0770 is showing up because the lock up clutch is not functioning properly. It could be that the clutch in the torque converter is worn out and is slipping or the solenoid itself is not operating correctly, it could be that the oil is dirty or ECM is no sending signal for the solenoid to operate. For 2WD without ABS, it doesn't have a speed sensor at the wheels, so it uses a speed sensor installed on the transmission normally close to the transaxle. If the gears on that speed sensor is not the correct number of tooths, then it mean it will give wrong speed reading.
It is also expected that during lockup the engine speed should be the same as the final drive speed sensor(with tolerance 50-200rpm). So if the wrong teeth was installed. It mean there will be conflicting speed readings from the crank shaft position sensor and the speed sensor installed on the transmission.
For your car with ABS, you don't have to worry about the speed sensor and because ECM is already replaced.
Firstly, Check correct oil level, perform flutching of the transmission and change the ATF- dirt can cause clogging
Secondly, check if the ECM powers the SL or S3 or the lockup solenoid. Check also if the solenoid operates. It make clicking noise. Or as the technician said just replace it.
Third, replace the torque converter if all the above is ok. It could that the lockup clutches are burnt, so it slips.
Hope this is helping
Wednesday, November 23rd, 2016 AT 1:05 PM