DTC 49, Service Throttle Soon Light Circuit Fault: Notes
SERVICE THROTTLE SOON light should always light when ignition is on and engine is not running for 2 seconds. PCM controls SERVICE THROTTLE SOON light by providing a ground path. DTC 49 will set when:
- Ignition voltage on SERVICE THROTTLE SOON light control circuit when PCM is requesting SERVICE THROTTLE SOON light on.
Or
- No ignition voltage on SERVICE THROTTLE SOON light control circuit when PCM is requesting SERVICE THROTTLE SOON light off.
PCM will default to MIL will not light, but a current and history DTC 49 will set.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- This step checks PCM's ability to command SERVICE THROTTLE SOON light.
- This step determines if an open is present in ignition feed circuit or SERVICE THROTTLE SOON light control circuit.