P1643 – Wait To Start Lamp Control Circuit Conditions

P1643 Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1643 Possible Causes

Faulty Wait To Start Lamp,Wait To Start Lamp harness is open or shorted,Wait To Start Lamp circuit poor electrical connection

P1643 Description

With the key on or engine running, then with the Wait To Start lamp requested on (Test 1), the Powertrain Control Module (PCM) detects that the voltage ON the lamp control circuit was high, or with the lamp requested off, that the voltage on the lamp control circuit was near zero (0) volts.