Transmission Slipping

(P0700) TRANSMISSION SLIPPING





When Monitored and Set Condition
- When Monitored: Engine RPM greater than 450 RPM, output speed greater than 180 RPM, no N2 - N3 input speed sensor errors present, no gear selector lever errors present, no ABS system errors, and all wheel speeds between 70 - 380 RPM with no wheel slip detected.
- Set Condition: Calculated ratio not within allowable range for the engaged gear. No shifting operation. The TCM constantly calculates the transmission ratio based on the N2 - N3 input speed signals and the calculated output shaft speed (CAN message from the ABS). The TCM will detect if the transmission is slipping or an invalid gear ratio is present.

POSSIBLE CAUSES
- OTHER DTCS PRESENT
- AXLE - MECHANICAL- GEAR RATIO
- INTERNAL TRANSMISSION
- TRANSMISSION CONTROL MODULE

Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT





Note: Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level in accordance with the Service Information.

Note: Always perform diagnostics with a fully charged battery to avoid false symptoms.
With the DRB III*, read the engine DTCs. Check and repair all engine DTCs prior to performing transmission symptom diagnostics.
With the DRB III*, read and record all Transmission DTCs.

Note: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Most DTCs set on start up but some must be set by driving the vehicle such that all diagnostic monitors have run.

Note: Verify flash level of transmission controller. Some problems are corrected by software upgrades to the transmission controller.

Note: Check for any Technical Service Bulletin that may apply.

Perform this procedure prior to Symptom diagnosis.
Continue
Go To 2

2. OTHER DTCS PRESENT





With the ignition on.
With the DRB III*, read Transmission DTCs.
Are any Improper Gear and/or Improper Ratio DTCs present?
Yes>>Refer to the Transmission - Electrical Diagnostics category and perform the appropriate symptom.
No>>Go To 3

3. AXLE - MECHANICAL - GEAR RATIO

Verify the correct axle gear ratio and make sure there are no mechanical problems. Refer to the Differential & Driveline category for the proper procedures.
Were any problems found?
Yes>>Refer to the Differential & Driveline category for proper repair procedures.
No>>Go To 4

4. INTERNAL TRANSMISSION

Determine if the Transmission is mechanically slipping.
Is the transmission slipping?
Yes>>Repair internal transmission as necessary. Refer to the Service Information for the proper repair procedure. Perform NAG1 TRANSMISSION VERIFICATION TEST.
No>>Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST. Verification Tests