DTC 57 Cruise Control Output Monitoring: Notes

Cruise control output monitoring circuit is used to determine the state of circuit No. 1679. When cruise control is engaged (the brake pedal is not depressed and ASR is not operating), cruise control cutoff relay completes engagement circuit through terminal "A" of connector C2 and terminal "C" of connector C1. When EBTCM supplies battery voltage to circuit No. 1679 (activating cruise control cutoff relay), cruise control circuit is opened by relay switch moving off relay terminal "A" of connector C2.

If circuit No. 1679 remains high when relay coil is energized (which should pull circuit low), the SERVICE ASR indicator light will illuminate and DTC 57 will be set.

1. Measures resistance in relay coil.
2. Checks for open in ground circuit No. 150.
3. Checks for open in circuit No. 1679.
4. Checks for short to battery voltage in circuit No. 1679, which would keep circuit No. 1679 high at all times.
5. Checks for EBTCM-switched short to battery voltage.
6. Checks for reset of DTC 57. If DTC 57 is reset after ensuring circuit No. 1679 is okay, EBTCM is detecting a problem in circuit No. 1679 when one does not exist.
7. Checks for correct system operation after replacing cruise control cutoff relay.
8. Checks for any remaining DTC-setting problems after replacing cruise control cutoff relay in step 7).