Diagnostic trouble code (DTC) information

Condition 

Fig 1: Transmission Input Speed Sensor (Speed Of Input Shaft)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The transmission speed signal is transmitted by a sensor on the transmission. The transmission control module (TCM) uses the signal to determine the input shaft speed after the torque converter. This signal is used to compare the transmission speed and vehicle speed. The transmission control module (TCM) uses this comparison to calculate gear-shift timing. Engine speed (RPM) and vehicle speed data affects the adjustment of system pressure, lock-up function control and engine torque reduction. The result is smooth gear-shifting. The control module calculates and compares the transmission speed, engine speed (RPM) and speed at the transmission. Diagnostic trouble code (DTC) TCM-0023 is stored if the control module registers that the engine speed (RPM) signal is missing.

Substitute Value 

• No torque reduction
• No lock-up

Possible Source 

• Contact resistance in the terminals.
• Open-circuit on power supply.
• Open-circuit in the signal cable.
• Defective input speed sensor.

Fault symptom[s] 

• General orange warning lamp lit.
• Malfunction indicator lamp (MIL) lit.
• No lock-up function.
• Harsh gear shifting.

HINT: Harsh gear shifting can be caused by: 

• No reduction of line pressure when shifting.
• No reduction of line pressure when moving the gear selector between positions P-R, N-R and N-D.
• No torque limiting request to engine control module (ECM) when shifting.