DTC Descriptor
DTC P0736: Incorrect Reverse Ratio
Diagnostic Fault Information
Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Circuit/System Description
The clutch pressure control (PC) solenoid 2 flows fluid to the 3-5-R clutch when commanded OFF and exhausts fluid when commanded ON. The clutch PC solenoid 2 regulates the transmission fluid pressure to the 3-5-R clutch. The transmission
fluid pressure (TFP) switch 1 Opens (high) under fluid pressure and closes (low) when no pressure is present. The transmission control module (TCM) calculates gear ratio based on data from the automatic transmission input speed sensor (ISS)
and the output speed sensor (OSS). The TCM compares the known transmission gear ratio to a calculated gear ratio for each commanded gear.
Conditions for Running the DTC
• | 3-5-R clutch is the primary on-coming clutch. |
• | The commanded gear is Reverse. |
Conditions for Setting the DTC
TFP Switch 1 = Low (No fluid pressure)
Action Taken When the DTC Sets
DTC P0736 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0736 is a Type A DTC.
Diagnostic Aids
When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. Ensure the transmission fluid level is correct and there are no leaks. If there are any other transmission
DTCs set, diagnose those first.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
DTC Type Reference
Electrical Information Reference
Circuit/System Verification
- Operate the vehicle to induce a shift from second to third gear while observing TFP Switch 1. Perform this action 2 times. The TFP Switch 1 should change states from Low to High.
⇒ | If the TFP Switch does not change states and no other DTCs set, replace the control solenoid (w/body and TCM) valve assembly. |
⇒ | If any other DTCs set, diagnose that DTC first. |
- Operate the vehicle to obtain sixth gear 2 times and then check for DTCs other than DTC P0736.
⇒ | If any other DTCs set, diagnose that DTC first. |
⇒ | If no other DTC sets, continue on with diagnostics. |
- Operate the vehicle by shifting from Park to Reverse, then while in reverse, operate the vehicle with the calculated throttle position greater than 8% for 5 seconds, perform this maneuver a minimum of 3 times.
⇒ | If the DTC P0736 resets, go to Component Testing. |
Component Testing
- Perform the
Line Pressure Check
.
- Inspect the check ball 5 for possible sticking or damage.
⇒ | If you found a concern with this check ball, repair the concern. |
- Inspect the shift select valve 3 for sticking or damage.
⇒ | If you found a concern with the shift select valve 3, repair or replace the valve or valve body. |
- Inspect the low and reverse clutch assembly for wear or damage.
⇒ | If you found a low and reverse clutch assembly concern, repair or replace the low and reverse clutch assembly as necessary. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
• | Control solenoid (w/body and TCM) valve assembly. Refer to
Control Module References
for replacement, setup, or programming. |