Allison 3000 & 4000 Gen5 Engine P0657 Fault Code Solution

This instruction show you guide on how to solve Allison 3000 & 4000 Gen5 engine fault code P0657 Actuator Supply Circuit Voltage 1 Open (HSD1).

 

For more Diesel machine repair,please refer to:

2023 Diesel DTC Solutions V2.9.98+ Diesel Explorer 2.0+Instruction

2024 2019 Allison DOC Transmission Diagnostic Software Free Download

 

 

DIAGNOSTIC RESPONSE:

SOL OFF, DNA, inhibit TCC operation, Inhibit main modulation

 

CIRCUIT DESCRIPTION:

This test detects if the voltage measured at the High Side Driver (HSD) shows that multiple low side drivers indicate open, but the HSD indicates high voltage.

 

1 The DTC sets while in a forward range, then shifts to another forward range. If failure occurs while in Neutral(N),the transmission remains in Neutral (N).If failure occurs while in Reverse(R), the transmission remains in Reverse (R) or shifts to Neutral (N). Once range is attained. transmission is locked in this range and there is no response to shift selector requests.

 

2 The TCM inhibits TCC engagement.

ACTION TAKEN WHEN THE DTC SETS:

When the DTC P0657 is active:

 

3 Main Modulation is inhibited.

 

4 DTC is stored in the TCM history.

 

5The CHECK TRANS light illuminates.

 

6 The TCM freezes shift adapts (DNA).

CONDITIONS FOR CLEARING THE DTC:

Use the diagnostic tool to clear the DTC from the TCM history.The TCM automatically clears the DTC from the TCM history if the vehicle completes forty warm-up cycles without failure.

DIAGNOSTIC AIDS:

DTC P0657 can be caused by:

1 HSD1 circuit issues such as:

– W111 shorted to another wire in chassis harness.

-W111 (terminal 1 of 20-way) shorted to another wire in the internal transmission harness.

– W111 open circuit in chassis harness.

-W111 (terminal 1 of 20-way) open circuit in internal transmission harness.

 

2 Two or more low side driver circuit issues with Main Mod,PCS4,or PCS6.

– W17 4 shorted to another wire in chassis harness.

– W174 shorted (terminal 8 of 20-way) to another wire in the internal transmission harness.

– W17 4 open circuit in chassis harness.

– W17 4 (terminal 8 of 20-way) open circuit in internal transmission harness.

 

3 Main Mod issues such as:

– W17 4 shorted to another wire in chassis harness.

-W17 4 shorted (terminal 8 of 20-way) to another wire in the internal transmission harness.

-W17 4 open circuit in chassis harness.

-W17 4 (terminal 8 of 20-way) open circuit in internal transmission harness.

 

4 PCS4 issues such as:

– W155 shorted to another wire in chassis harness.

– W155 shorted (terminal 2of 20-way) to another wire in the internal transmission harness.

– W155 open circuit in chassis harness.

-W155 (terminal 2of 20-way) open circuit in internal transmission harness.

-PCS4 solenoid open or shorted.

 

5 PCS6 (7-speed only) issues such as:

– W178 shorted to another wire in chassis harness.

– W178 shorted (terminal 7 of 20-way) to another wire in the internal transmission harness.

– W178 open circuit in chassis harness.

– W178 (terminal 7 of 20-way) open circuit in internal transmission harness.

 

6 Defective solenoids Main Mod, PCS4,and PCS6.

7 Unlocked connectors, expanded terminals, poor pin crimps or unlocked pins causing high resistance or open circuit.

 

8 Defective TCM.

More Allison repair case,please refer to Allison Trouble Repair