Transmission Control System Malfunction
What does P0700 mean?
The P0700 code means the vehicle's onboard diagnostic system has detected: Transmission Control System Malfunction. This is a serious severity code.
Common Symptoms
- Check Engine Light and transmission warning light on
- Harsh or erratic shifting
- Vehicle may be stuck in one gear (limp mode)
- Transmission slipping
Probable Causes (Ranked by Likelihood)
- Fault in the transmission control module (TCM) or its circuits High
- Hydraulic fault in the transmission (solenoid, pressure) High
- Wiring fault in transmission control circuit Moderate
- Low or contaminated transmission fluid Moderate
Step-by-Step Diagnostic Procedure
-
P0700 is a generic indicator -- it means the TCM has detected a fault and illuminated the MIL. Always scan for additional transmission-specific codes (P07xx range) which will identify the exact fault.
-
Check transmission fluid level and condition. Dark, burnt-smelling fluid indicates serious wear.
-
Inspect the transmission wiring harness at the transmission connector for damaged or corroded pins.
-
With additional codes, diagnose the specific solenoid, sensor, or circuit identified.
Frequently Asked Questions
Does P0700 mean my transmission is ruined?
Not necessarily. P0700 is a gateway code that just means a transmission fault exists. Read the accompanying specific codes. Many P0700 issues are caused by a single failed solenoid or sensor and are relatively inexpensive to fix.