DTC 72

Wiring Diagram:

CIRCUIT DESCRIPTION
The Serial Data Link is an asynchronous link operating at 8192 bits per second.

Code 72 will set and the red brake warning lamp will illuminate if the EBTCM does not get polled by the BCM for information, or if it does not see PCM information on the data link.

TEST CONDITION(S)
1. Tested continuously.

FAILURE CONDITION(S)
1. While Standing or Driving: Serial Data communications are lost.

ACTION TAKEN
1. Code set.
2. ABS and TCS switched "OFF."
3. Red brake warning lamp ON.
4. ABS and TCS "DISABLED" messages ON.

TEST DESCRIPTION
Test numbers refer to circled numbers on the diagnostic chart.
1. This test checks to see if the off-board device can communicate with the EBTCM.
2. This test checks for a short to battery in the serial data circuit.
3. This test checks for a short to ground in the serial data circuit.
4. This test checks for an open in the serial data circuit.
5. This test checks to see if the off-board device can communicate with the EBTCM.
6. If the connections at the EBTCM and DLC connector are OK, replace the EBTCM.

DIAGNOSTIC AIDS
The problem may be intermittent. Try performing the tests shown while "wiggling" wiring and connectors; this can often cause the fault to appear.

NOTICE: Diagnostic Trouble Code TO72 will never be displayed while serial data fault is current. A current Code 72 will result in a "NO TCS DATA, ANTILOCK DISABLED" and "TCS DISABLED" messaged as well as BCM Diagnostic Trouble Code B332 and PCM Code P133.