Code 75 - Pcm-To-EBTCM Serial Data Malfunction - (With TCS): Notes

Serial data communications circuit is used to transmit messages from one electronic control unit to another when interface is necessary between systems. The ABS VI/TCS systems depends on information from PCM for proper operation.

Code 75 will set when vehicle speed is greater than 3 MPH and a malfunction is present in serial data circuit, or if PCM has not broadcasted a serial message for at least 10 seconds. When a malfunction code is stored, TCS is disabled and TCS warning light is illuminated.

NOTE: Test numbers refer to numbers on diagnostic chart. Use only 10-megohm (minimum) DVOM for all voltage and resistance tests. For identification of circuits and terminals referenced in charts and text, see WIRING DIAGRAMS .

Fig 1: Code 75 Diagnostic Flow Chart - (With TCS)

Checks test equipment.
Checks other systems on the circuit.
Checks for short to ground on serial data line.
Checks for short to voltage on serial data line.
Checks for poor terminal contact or corrosion causing malfunction.
Attempts to establish communication with modules.