P1637 Engine Trouble Code
What is P1637?
P1637 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Code: | P1637 |
P1637 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
P1637 Code Structure
Understanding what each digit means in the P1637 powertrain trouble code:
| P | 1 | 6 | 3 | 7 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Temperature Sensor B Circuit Range/Performance | Injection Pump Fuel Metering Control 'A' High | Shift/Timing Solenoid Malfunction |
How to Fix P1637
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
P1637 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
P1637 Description
P1637 engine trouble code is related to Shift/Timing Solenoid Malfunction.
Main Cause
The primary reason for P1637 OBD-II Engine Trouble Code is: Fuel Temperature Sensor B Circuit Range/Performance.