P1902: Kickdown Solenoid Relay Control Circuit Failure
The P1902 code indicates a malfunction in the control circuit of the kickdown solenoid relay. This relay is responsible for activating the kickdown solenoid, which downshifts the transmission when the accelerator is fully depressed. A failure in this circuit can prevent the transmission from downshifting properly, leading to poor acceleration and potential transmission damage.
01. Most Common Causes
- Faulty kickdown solenoid relay
- Open or shorted wiring in the relay control circuit
- Corroded or loose electrical connectors
- Failed transmission control module (TCM)
02. Symptoms You Will Notice
- Lack of power during hard acceleration
- Transmission fails to downshift when passing or climbing
- Check Engine Light illuminated
- Harsh or erratic shifting
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the kickdown solenoid relay and its wiring for damage or corrosion.
Step 3: Test the relay's coil resistance and switching operation with a multimeter.
Step 4: Check for voltage and ground at the relay control circuit from the TCM.
Step 5: If all else is fine, test the kickdown solenoid itself for proper operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause poor acceleration and may lead to transmission damage over time.
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.