P0700 on a 2017 GMC Sierra 1500
Transmission Control System Malfunction
P0700 on a 2017 GMC Sierra 1500 indicates transmission control system malfunction. It usually stays drivable short-term but should be diagnosed promptly. The most common cause is low or burnt transmission fluid (typically $100–$350). Confirm the root cause before replacing parts.
What does P0700 mean on a 2017 GMC Sierra 1500?
P0700 is an "informational" code set by the engine control module when the transmission control module (TCM) reports any fault. P0700 itself does not identify a specific transmission problem — it is a flag that tells you to scan the TCM for the underlying code or codes. The actual fault could be anything from a shift solenoid failure to a slipping clutch pack to a low-fluid condition.
This guide covers P0700 across the 2015-2019 GMC Sierra 1500 generation — the symptoms, causes, and diagnostic steps below apply to every model year from 2015 through 2019.
Is it safe to drive a 2017 GMC Sierra 1500 with P0700?
In most cases a 2017 GMC Sierra 1500 stays drivable for short trips with P0700 active, but diagnose and repair it promptly. This is a high-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0700 on a 2017 GMC Sierra 1500?
- Check Engine Light is illuminated
- Transmission stuck in a single gear (often 3rd or 4th — "limp mode")
- Hard, delayed, or erratic shifts
- Torque converter clutch not locking up on the highway
- Higher than normal RPM at cruise
- Reduced fuel economy
- Possible transmission slipping under load
What causes P0700 on a 2017 GMC Sierra 1500?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Low or burnt transmission fluid Always check fluid level and condition first; many P0700s clear with a fluid and filter service. | Most common | $100–$350 |
| Failed shift solenoid (one or more) | Common | $250–$900 |
| Failed transmission speed sensor (input or output) | Common | $150–$500 |
| Worn or stuck valve body | Occasional | $600–$2,000 |
| Internal mechanical wear — slipping clutch packs or bands | Occasional | $2,500–$6,000 |
| Failed transmission control module (TCM) itself | Rare | $500–$1,500 |
| Wiring harness damage to TCM or solenoid pack | Occasional | $200–$700 |
How to diagnose this on a 2017 GMC Sierra 1500
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Scan the TCM for the specific transmission code
P0700 alone is not actionable. Use a scan tool capable of reading transmission codes (not just engine codes) to retrieve the actual P07XX, P08XX, or P09XX code that triggered the P0700. That code is what to act on.
Tools: Scan tool with TCM access
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Check fluid level, color, and smell
Most modern transmissions require checking fluid at operating temperature with the engine running and the selector in park or neutral, on a level surface. Dark, brown, or burnt-smelling fluid indicates clutch material in the fluid — fix the root cause; do not just refill.
Tools: Lift or jack and stands (sealed-for-life units), Vehicle-specific fluid spec
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Inspect the wiring at the transmission case
The external transmission harness is exposed to heat, oil, and road debris. Disconnect, inspect, and reconnect every external connector. A connector full of transmission fluid points to a leaking case seal that has wicked fluid up the harness — replace the seal and sometimes the harness.
Tools: Connector unlock tool, Electrical cleaner
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Pan-drop and inspect the filter and magnet
Drop the pan and inspect the filter, gasket sealing surface, and the magnet on the bottom of the pan. A magnet covered in fine metallic paste is normal. Large chunks of metal or clutch material indicate internal failure — at that point a teardown or replacement is required.
Tools: Drain pan, Socket set, New filter and gasket
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Verify TCM and ECM are talking on the CAN bus
Use the scan tool to read live data from both modules simultaneously. If the ECM sees a vehicle speed that disagrees with the TCM, suspect a speed sensor or harness fault. If the TCM is non-responsive, check power, ground, and CAN bus continuity to the module.
Tools: Scan tool with bi-module live data, Multimeter
NHTSA complaints & recalls for the 2017 GMC Sierra 1500
Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2017 GMC Sierra 1500. Use these to gauge how common a problem is on your specific vehicle before you start chasing GMC Sierra 1500 diagnostics.
- POWER TRAIN 142
- ENGINE 62
- SERVICE BRAKES 127
- ELECTRICAL SYSTEM 60
- UNKNOWN OR OTHER 41
5 active recalls
- SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM Sep 2019
General Motors LLC (GM) is recalling certain 2015-2017 Cadillac Escalade, 2014-2018 Chevrolet Silverado, GMC Sierra, 2015-2018 Chevrolet Suburban, Tahoe, GMC Yukon vehicles. The amount of vacuum created by the vacuum pump may decrease over time.…
NHTSA campaign 19V645000 - SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:WHEEL SPEED SENSOR/TONE RING Oct 2019
General Motors LLC (GM) is recalling certain 2015-2020 Chevrolet Suburban, Tahoe, and GMC Yukon, and 2014-2018 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles equipped with a 5.3-liter engine, a 3.08-ratio rear axle and four-wheel drive. If a wheel-speed sensor fails, whil…
NHTSA campaign 19V761000 - AIR BAGS:FRONTAL Sep 2016
General Motors LLC (GM) is recalling certain model year 2015-2017 Chevrolet Silverado 2500 HD, 3500 HD, Tahoe, Suburban, GMC Sierra 2500 HD and 3500 HD, GMC Yukon, GMC Yukon XL, Cadillac Escalade and Cadillac Escalade ESV vehicles and 2014-2017 Chevrolet Corvette, Silverado 1500…
NHTSA campaign 16V651000 - CHILD SEAT:TETHER: CONNECTOR/CLIP Aug 2017
General Motors LLC (GM) is recalling certain 2017 Chevrolet Silverado 1500, and GMC Sierra 1500 trucks. The owner's manual for the affected vehicles may be missing instructions on how to use the tether anchorage and child restraint anchorage systems. As such, these vehicles fai…
NHTSA campaign 17V487000
How do I fix P0700 on a 2017 GMC Sierra 1500?
- Service the transmission fluid and filter to OEM specification
- Replace failed shift solenoid(s)
- Replace failed input or output speed sensor
- Replace or rebuild the valve body
- Replace the TCM
- Major rebuild or replacement of the transmission for internal failures
About the 2015-2019 GMC Sierra 1500
The 2015-2019 GMC Sierra 1500 was commonly sold with the following powertrains: 5.3L V8, 6.2L V8, 2.7L Turbo I4, 3.0L Duramax I6 Diesel. Common trims include Pro, SLE, Elevation, SLT, AT4, Denali.
Why P0700 by itself is not a diagnosis
P0700 is set in the ECM because the TCM reported a problem. The TCM stored the actual code. Many cheap OBD-II scanners only read engine codes — they will show P0700 with no further detail, leading to wasted parts swaps. A scan tool that can read transmission codes is essential for diagnosing P0700 efficiently.
P0700 with limp mode (stuck in one gear)
When the TCM detects a fault that could damage the transmission, it commands a default gear (often 3rd or 4th) and disables all shifting. This is “limp mode.” It is meant to let you drive a short distance to a shop, not for daily driving. Continuing to drive in limp mode for weeks can damage internal components even though the limp logic exists to prevent damage.
When to fluid-service vs rebuild
If the underlying transmission code is for a solenoid, sensor, or wiring issue and the fluid is clean, a fluid and filter service plus the failed electrical part is the right repair. If the underlying code is for ratio incorrect (P0731–P0734), torque converter clutch (P0741), or excessive clutch slip, the transmission has mechanical wear and a full rebuild or replacement is more cost-effective than chasing individual parts.