P0700 - Transmission Control System (MIL Request)
P0700 is a generic powertrain diagnostic trouble code indicating Transmission Control System (MIL Request). It relates to the Transmission system.
DTC Breakdown (SAE J2012)
| System | Powertrain (P) |
| Type | Generic |
| Subsystem | Transmission |
| Fault Index | 00 |
| Standard | SAE J2012 / ISO 15031-6 |
What does diagnostic code P0700 mean?
The engine control module logged P0700 as an informational flag indicating that the Transmission Control Module (TCM) has detected a transmission system fault and requested check engine light illumination. You must scan the TCM directly to retrieve the specific transmission sub-codes (e.g., shift solenoid or torque converter codes) to begin diagnostics.
Severity Level & Driveability Details
Severity: High
Variable. The severity depends entirely on the specific transmission trouble code stored inside the TCM, ranging from minor sensor issues to severe mechanical gear slippage.
Common Symptoms of P0700
- Check engine light illuminated on the dashboard.
- Companion sub-codes stored inside the Transmission Control Module (TCM) that must be scanned to find the root cause.
- Varying transmission symptoms (such as harsh shifting or limp mode) depending on the specific underlying TCM codes.
Typical Causes for P0700
- A transmission solenoid, sensor, or pressure fault detected by the TCM (scan the TCM to identify the companion code).
- TCM communication circuit wiring harness damage on the CAN bus.
- Failed Transmission Control Module (TCM) or PCM communication error.
Diagnostic and Troubleshooting Steps
Connect an advanced scan tool capable of communicating with the Transmission Control Module (TCM). Retrieve the specific codes stored in the TCM (such as gear ratio or solenoid codes) which contain the actual source of the malfunction.
Typical Repairs and Fixes
- Scanning the TCM directly to retrieve the companion transmission-specific trouble sub-codes.
- Addressing the specific solenoid, sensor, or hydraulic valve body fault reported by the TCM.
- Topping off or changing transmission fluid and filter if fluid is low or burnt.
Sensor Location & Parts Involved
The transmission solenoids and sensor are located inside the transmission pan on the valve body.
Clearing Code & Recurrence
Reset codes to verify the transmission operates correctly.
Emissions & Smog Inspection Impact
High RPMs in limp mode increase exhaust emissions and reduce fuel mileage.
Free Check Engine Code Cheat Sheet (PDF)
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Sources & References
This diagnostic guide is compiled and verified against the following authority sources:
- NHTSA TSB safety reports
- SAE J2012 standard definitions
Frequently Asked Questions about P0700
What does the transmission control system malfunction MIL request code P0700 mean?
The engine control module logged P0700 as an informational flag indicating that the Transmission Control Module (TCM) has detected a transmission system fault and requested check engine light illumination. You must scan the TCM directly to retrieve the specific transmission sub-codes (e.g., shift solenoid or torque converter codes) to begin diagnostics.
Is it safe to drive with the transmission control system malfunction MIL request code P0700 active?
No, transmission slipping can leave you stranded.
How much does it cost to repair a transmission control system malfunction MIL request code P0700 fault?
Scanning codes is $50-$100. Repairs can range from a $150 shift solenoid to a $2,000-$4,000 transmission rebuild, depending on TCM codes.
What are the common causes of the transmission control system malfunction MIL request code P0700?
Trigger conditions for the transmission control system malfunction MIL request code P0700 include: A transmission solenoid, sensor, or pressure fault detected by the TCM (scan the TCM to identify the companion code)., TCM communication circuit wiring harness damage on the CAN bus., Failed Transmission Control Module (TCM) or PCM communication error..
Can I clear the check engine light for transmission control system malfunction MIL request code P0700?
Reset codes to verify the transmission operates correctly.
Will the transmission control system malfunction MIL request code P0700 cause an inspection failure?
High RPMs in limp mode increase exhaust emissions and reduce fuel mileage.