B1638 Engine Trouble Code
What is B1638?
B1638 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B1638 |
B1638 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
B1638 Code Structure
Understanding what each digit means in the B1638 body trouble code:
| B | 1 | 6 | 3 | 8 |
|---|---|---|---|---|
| Body Code | Fuel And Air Metering | Fuel Temperature Sensor B Circuit Range/Performance | Injection Pump Fuel Metering Control 'A' High | Clutch Position Sensor Circuit Malfunction |
How to Fix B1638
Diagnostic Steps:
Regarding B1638, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
VSS concerns may stem from noisy input signals caused by RFI/EMI from ignition wires, charging circuits, or aftermarket equipment. Verify VSS reads 0 mph when transmission is in Park.
Technical Notes:
B1638 DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
B1638 Description
B1638 engine trouble code is related to Clutch Position Sensor Circuit Malfunction.
Main Cause
The primary reason for B1638 OBD-II Engine Trouble Code is: Fuel Temperature Sensor B Circuit Range/Performance.