P1902: Kickdown Solenoid Relay Control Circuit Failure
The P1902 code indicates a malfunction in the kickdown solenoid relay control circuit. The kickdown solenoid is responsible for downshifting the transmission when the accelerator is fully depressed (kickdown). When the powertrain control module (PCM) detects an open or short circuit in the relay control circuit, it sets this code. This can lead to improper transmission operation, such as delayed or harsh downshifts, and may affect vehicle performance.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission fails to downshift when accelerating hard
- Harsh or delayed downshifts
- Reduced fuel economy
2. Most Common Causes
- Faulty kickdown solenoid relay
- Open or shorted wiring in the relay control circuit
- Corroded or loose electrical connectors
- Failed PCM (rare)
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related transmission codes.
Step 2: Visually inspect the kickdown solenoid relay and its wiring for damage, corrosion, or loose connections.
Step 3: Test the relay using a multimeter to check for continuity and proper operation.
Step 4: Check the control circuit voltage at the PCM connector; repair or replace as needed.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the transmission may not downshift properly, leading to reduced performance and potential transmission damage.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the relay or wiring needs replacement.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.