DTC P1759

BHE050201026W28

DTC P1759

2-4 brake fail-safe valve malfunction

DETECTION CONDITION

• TCM detects 2-4 brake fail-safe valve malfunction.

Diagnostic support note:

• This is continuous monitor (CCM).
• AT warning light illuminates if TCM detects the above malfunction conditions in two consecutive drive cycles.
• PENDING CODE is available.
• FREEZE FRAME DATA is available.
• MIL does not illuminate.
• DTC is stored in TCM memory.

POSSIBLE CAUSE

• Stuck 2-4 brake fail-safe valve
• Oil pressure switch B stuck on
• Short to ground in oil pressure B system wiring harness
• Poor connection of connectors in oil pressure switch B system wiring harness

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Verify related Service Bulletins and/or on-line repair information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3

INSPECT FOR DTC

• Turn the ignition switch to the ON position (engine off).
• Inspect for DTCs.
• Are any other DTCs output?
Yes
Follow the applicable DTC inspection procedure.
No
Go to the next step.
4

INSPECT ATF CONDITION

• Turn the ignition switch to the LOCK position.
• Inspect ATF condition.
– Transparent red: Normal
– Milky: Water mixed in fluid
– Reddish brown: Deteriorated ATF
• Is it normal?
Yes
Replace the control valve body, then go to the next step.
No
If the ATF color milky or reddish brown, repair or replace AT, then go to the next step.
5

VERIFY TROUBLESHOOTING OF DTC P1759 COMPLETED

• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the TCM memory using the WDS or equivalent.
• Drive the vehicle in D range and make sure that the gears shift smoothly from 1GR to 4GR.
• Is the same DTC present?
Yes
Replace the TCM, then go to the next step.
No
Go to the next step.
6

VERIFY AFTER REPAIR PROCEDURE

• Perform the "After Repair Procedure".
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.