Possible Causes
Faulty Smart Driver Unit (SDU)
Faulty Hydraulic Pump
Hydraulic Pump harness is open or shorted
Hydraulic Pump circuit poor electrical connection
Faulty Transmission Control Module (TCM)
الأسباب المحتملة
Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
الأعراض المحتملة
Description
This diagnostic checks the performance of the hydraulic pump. The Smart Driver Unit (SDU) which is external to the Transmission Control Module (TCM) drives the hydraulic pump based upon a PWM command signal received from the Transmission Control Module (TCM). This diagnostic uses three feedback signals. The PWM driver, internal to TCM, returns a command feedback signal. The SDU returns to the TCM the hydraulic pump driver feedback signal. The TCM separately receives the hydraulic pump feedback signal confirming the pump state.
