Drive Cycle Test
NOTE:
This test will provide information on symptom evaluations, symptom repeatability, and repair verification.
- If possible, drive on wet road condition and have assistant monitor wheels during ABS stop. Drive at 10 MPH, press brake pedal hard enough to lock all wheels. If one wheel locks consistently and if ABS warning light does not come on, see WHEELS LOCK UP under INTERMITTENT FAILURES. If ABS warning light comes on, go to step 7) . If one wheel does not lock up consistently and ABS warning light does not come on, go to next step.
- Drive vehicle at 20 mph. Perform light-to-medium stop. If pump motor turns on and brake pulsations are felt, and if ABS warning light comes on, see ABS MISFIRE, TOO SENSITIVE, ACTIVATES ON NORMAL STOPS under INTERMITTENT FAILURES. If ABS warning light comes on and stays on, go to step 7) . If preceding does not happen and other symptoms are present, go to step 6) . If ABS warning light does not come on, go to next step.
- Connect NGS tester or scan tool and clear any continuous DTCs. Turn ignition off, then start and idle vehicle. Allow vehicle to creep forward at idle for at least 45 seconds. If ABS warning light comes on, go to step 8) . If light does not come on, go to next step.
- Clear any continuous DTCs. Turn ignition off. Start vehicle and slowly accelerate to 25 MPH, making sure this takes at least 45 seconds. If ABS warning light comes on, go to step 8) . If light does not come on, go to next step.
- If customer concern has been addressed and corrected by previous steps, test is complete. If concerns remain, go to INTERMITTENT FAILURES .
- Test for lack of sufficient deceleration during braking or if vehicle pulls and pump motor does not come on. If either symptom occurs, go to INTERMITTENT FAILURES . If neither symptom occurs, problem is not in ABS system. See appropriate DISC & DRUM article for diagnosis.
- Connect NGS tester or scan tool and retrieve codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If DTC is same as before and proper Pinpoint Test has been completed, go to INTERMITTENT FAILURES . If Pinpoint Test is not complete, return to last step and complete test. If different DTC is retrieved, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS table. If ABS control module does not respond, go to SYSTEM PRE-CHECK .
- Retrieve and record continuous DTCs. If sensor code is obtained, see DIAGNOSTIC TROUBLE CODE DEFINITIONS table. If no code or no SYSTEM PASS is obtained, see SYSTEM PRE-CHECK .
DIAGNOSTIC TROUBLE CODE DEFINITIONS
| DTC | Circuit Description | Go To Test | ||
|---|---|---|---|---|
| None | ABS Light On With System Pass | A | ||
| B1318 | ABCM - Low Voltage | Q | ||
| B1342 | ABCM Failure | (1) | ||
| C1095 | HCU Pump Motor - Circuit Shorted | B | ||
| C1096 | HCU Pump Motor - Circuit Open | C | ||
| C1115 | ABS Relay Shorted | D | ||
| C1140 | Excessive Dump Time Fault | E | ||
| C1145 | Right Front Sensor (Static) | F | ||
| C1148/C1234 | Right Front Sensor (Dynamic) | G | ||
| C1155 | Left Front Sensor (Static) | F | ||
| C1158/C1233 | Left Front Sensor (Dynamic) | G | ||
| C1165 | Right Rear Sensor (Static) | H | ||
| C1168/C1235 | Right Rear Sensor (Dynamic) | J | ||
| C1175 | Left Rear Sensor (Static) | H | ||
| C1178/C1236 | Left Rear Sensor (Dynamic) | J | ||
| C1184 | Excessive ABS Isolation | K | ||
| C1185 | Open ABS Relay | L | ||
| C1194/C1196 | Left Front Dump Solenoid | N | ||
| C1198/C1200 | Left Front Isolation Solenoid | M | ||
| C1210/C1212 | Right Front Dump Solenoid | N | ||
| C1214/C1216 | Right Front Isolation Solenoid | M | ||
| C1220 | ABS Warning Indicator - Shorted | P | ||
| C1222 | Wheel Speed Error | P | ||
| C1242/C1244 | Left Rear Dump Solenoid | N | ||
| C1246/C1248 | Right Rear Dump Solenoid | N | ||
| C1250/C1252 | Left Rear Isolation Solenoid | M | ||
| C1254/C1256 | Right Rear Isolation Solenoid | M | ||
| None | No Communication With Module | R | ||
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