Component Tests and General Diagnostics
TROUBLESHOOTING HINTS
Try the following checks before doing the System Check.
1. Check vacuum hose for leaks, kinks, and/or restrictions. Also check Cruise Control Servo linkage.
2. If the system works except for the Tap-Up and Tap-Down functions, replace the Cruise Control Module (V6 VIN 3 and V6 VIN W).
Go to System Check for a guide to normal operation.
Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK (ROAD TEST)
Use the System Check Table as a guide to normal operation.
Refer to System Diagnosis when a result is not normal.
SYSTEM DIAGNOSIS
Use the Isolation Test to choose the proper diagnostic tests.
Note: Do not press both the SET and R/A Switches at the same time while the engine is running.
If the Quick Checker displays a short light, release the switches immediately. Short can damage the Quick Checker.
TEST A: CRUISE SWITCH SHORT
Check for shorts to voltage in the wires to terminals G (BRN), A (GRY), M (GRY/BLK) and L (DK BLU). If the wires are good, replace the Multi- Function Lever.
TEST B: POWER CIRCUIT OPEN
1. Check the RADIO Fuse.
2. Check that terminal J (BLK) is grounded.
3. Disconnect connector C235 and check for battery voltage at terminal A (BRN/WHT) of the harness half with Ignition in RUN. If battery voltage is missing, check/repair PNK/BLK (39) V6 VIN 3 wire, BRN/WHT, (141) V6 VIN W wire and YEL (43) wire.
4. Check continuity between terminals A (BLU) and B (GRN) of the pin half of connector C235 with the Cruise Switch ON. If the switch is open, replace the Multi-Function Lever.
5. Check for an open in GRY (397) wire between terminal B of connector C235 and terminal A of the Cruise Control Module connector.
TEST C: BRAKE CIRCUIT OPEN
1. Check for an open Brake Switch.
2. Check for an open in the BRN (86) wire to terminal G of the Cruise Control Module.
TEST D: VENT CIRCUIT OPEN
If you are testing with a digital meter and have measured less than 30 ohms, perform Test J. Otherwise, remove the connector from the Cruise Control Servo. Measure the resistance between terminals A (DK BLU/WHT) and C (BLK) of the Servo. If it is greater than 55 ohms, replace the Servo. If it is less than 55 ohms, check for an open DK BLU/WHT (403) wire between terminal C of the Module and terminal A of the Servo. Check that terminal C of the Servo connector is grounded.
TEST E: VAC CIRCUIT OPEN
If you are testing with a digital meter and you measured less than 30 ohms, perform Test H. Otherwise, remove the connector from the Cruise Control Servo. Measure the resistance between terminals E (LT GRN) and C (BLK) of the Servo. If it is more than 55 ohms, replace the Servo. If it is less than 55 ohms, check for an open in the LT GRN (402) wire between terminal K of the Module and terminal E of the Servo. Check that terminal C (BLK) of the Servo Connector is grounded.
TEST F: SPS CIRCUIT OPEN
If you are testing with a digital meter and you measured less than 15 ohms, perform Test N. Otherwise, remove the connector from the Cruise Control Servo. Measure the resistance between terminals B (TAN) and D (LT BLU/BLK) of the Servo. If it is more than 25 ohms, replace the Servo. If it is less than 25 ohms, check for an open in the LT BLU/BLK (399) wire between terminal H of the Module and terminal D of the Servo. Check for an open in the TAN (398) wire between terminal F of the Module and terminal B of the Servo.
TEST G: SC CIRCUIT OPEN
Disconnect C235 and check the switch continuity between terminals B (GRN) and C (RED) of the pin half with the Set Switch pressed. If the switch is open, replace the Multi-Function Lever. If the switch is not open, check for an open in the DK BLU (84) wire between terminal C of connector C235 and terminal L of the Module.
TEST H: VAC CIRCUIT SHORT
Remove the connector from the Servo and measure resistance between terminals C (BLK) and E (LT GRN) of the Servo. If it is less than 30 ohms, replace the Cruise Control Servo. If it is 30 ohms or more, check for a short to ground in the (LT GRN) wire from terminal K of the Module to terminal E of the Servo.
TEST I: R/A CIRCUIT OPEN
Disconnect C235 and check switch continuity between terminals A (BLU) and D (YEL) of the pin half of the Cruise Switch in R/A. If the switch is open, replace the Multi-Function Lever. If the switch is not open, check for an open in the GRY/BLK (87) wire between terminal D of connector C235 and terminal M of the Module.
TEST J: VENT CIRCUIT SHORT
Remove the connector from the Servo and measure resistance between terminals A (DK BLU/WHT) and C (BLK) of the Servo. If it is less than 30 ohms, replace the Servo. If it is 30 ohms or more, check for a short to ground in the (DK BLU/WHT) wire from terminal C of the Module to terminal A of the Servo.
TEST K: VSS CIRCUIT OPEN
If the VSS light does not come on, or the voltage between terminals A and D remains less than 7 volts, check for an open in the RED (381) wire from the Vehicle Speed Sensor Buffer.
TEST L: VSS CIRCUIT SHORT
If the VSS light does not go off or battery voltage remains between terminals A and D, check for a short to ground on the RED (381) wire from the Vehicle Speed Sensor Buffer.
TEST M: VACUUM SYSTEM
1. Check for a blocked or leaking vacuum source.
2. If the vacuum source is good, plug the Vacuum Release Port and repeat Test 6 of the Isolation Test. If the vacuum now holds the throttle open, replace or repair the Vacuum Release Valve or the hose to it. If the test falls, replace the Cruise Control Servo.
TEST N: SPS CIRCUIT SHORT
Disconnect the Cruise Control Servo connector and repeat Test 7 of the Isolation Test. If the resistance is now over range, replace the Cruise Control Servo. If the resistance is still low, find and repair the short in the (TAN) wire from terminal F of the Cruise Control Module to terminal B of the Cruise Control Servo.
TEST O: SPS SHORT
If all other tests were OK, replace the Cruise Control Servo.
TEST P: CRUISE CONTROL MODULE
1. (VIN W only) Check the resistance between grounds G102 and G112. If it is more than 0.1 ohm, clean and tighten both grounds and the negative battery cable. In cases where the ground circuit is suspect, add a ground strap between the engine block and the bulkhead.
2. Connect a new Cruise Control Module and check for normal operation. If the Cruise Control operates normally, leave the new module in permanently. If the Cruise Control still does not operate normally, refer to the AC Custom Cruise 3 Systems Service Manual for further diagnostic procedures.