Test Description

Number(s) below refer to step number(s) on Diagnostic Table.

1. 1. The On-Board Diagnostic (OBD II) System Check prompts technician to complete some basic checks and store freeze frame and failure records data on scan tool if applicable. This creates an electronic copy of data taken when malfunction occurred. The information is then stored on scan tool for later reference.
2. 3. Normally, ignition feed voltage is present on output driver circuit with PCM/ECM disconnected and ignition turned ON.
3. 4. Checks for a shorted component or a short B+ on output driver circuit. Either condition would result in a measured current of over 1.5 amps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 amps.
4. 5. Checks for a fault component.
5. 14. The replacement PCM/ECM must be reprogrammed.

Fig 1: DTC P1640: ODM Internal SPI Communication (1 Of 2)

Courtesy of DAEWOO

Fig 2: DTC P1640: ODM Internal SPI Communication (2 Of 2)

Courtesy of DAEWOO