DTC 72

Fig. 157 Code 72: Serial Data Link Fault.:

DTC 72: Serial Data Link Fault:

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

Code 72 will set and the "ANTILOCK" indicator will illuminate if the EBTCM/EBCM does not get polled by the IPC 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. "ANTILOCK" indicator "ON."
4. "TRACTION DISABLED" message ON (vehicles with TCS).

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/EBCM.
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/EBCM.
6. If the connections at the EBTCM/EBCM and DLC connector are OK, replace the EBTCM/EBCM.

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 72 will never be displayed while serial data fault is current. A current Code 72 will result in a "NO TCS DATA", and "TRACTION DISABLED" messages as well as IPC Diagnostic Trouble Code B332 and PCM Code P133.