P0737
TCM Engine Speed Output Circuit
Transmission control module output
Generic OBD-II
High
What it means
P0737 means the transmission control module found a fault in the circuit it uses to output the engine-speed signal to other modules. That signal helps coordinate shifting and dashboard data, so a wiring, connector, or module fault here can cause harsh or incorrect shifts, erratic tachometer data, and sometimes a protective limp mode.
High
Can I keep driving? Usually drivable, but shifting may be off because the transmission controller can't share the engine-speed signal correctly. Have it diagnosed soon.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh, delayed, or incorrect shifting
- Erratic engine-speed / tachometer data shared between modules
- Transmission may enter limp / fail-safe mode
Common causes
Most likely first
- Wiring or connector fault in the TCM engine-speed output circuitLikely
- Poor ground or power to the transmission control moduleCommon
- Corroded or damaged connector pinsCommon
- Internal transmission control module faultLess often
- Related module or network communication issueLess often
How to diagnose & fix
Work through it in order
- Scan for codes and check whether other modules report matching engine-speed or communication faults.
- Inspect the output-circuit wiring and connectors for damage, corrosion, or looseness.
- Check the TCM's power feeds and grounds.
- Verify the engine-speed signal on the output circuit with a scope or meter.
- Repair the wiring/connector, or test the TCM if the circuit is sound. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0737?+
Usually yes for short trips, but the transmission may shift poorly or go into limp mode because the engine-speed signal it passes on is unreliable. Get it checked promptly.
Can I just clear P0737?+
It returns until the output-circuit wiring or the module is repaired. Fix the circuit rather than repeatedly clearing the code.
Related codes
Often seen with P0737
Read & clear P0737 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX