Test G: DTC 1-2-1-3: Test

Turn ignition off. Disconnect ABS control unit connector. Inspect terminals No. 3 and 18 for poor or loose connection, dirt or corrosion. Repair as necessary. If terminals are in good condition, measure resistance between harness terminals No. 3 and 18. Resistance should read between 3-6 ohms. If reading is as specified, go to step 4). If reading is not as specified, go to next step.
Disconnect HCU connector. See Figure . Check for an open or short from ABS control unit terminal No. 18 (Blue/White wire) to HCU harness connector terminal No. 3. Also check from ABS harness terminal No. 3 (Yellow wire) to HCU harness terminal No. 13 (Blue wire) for an open or short. Repair as necessary. If an open or short is not found, go to next step.
Disconnect HCU harness connector. Inspect terminals No. 3 and 13 of harness and HCU for damaged terminals, poor or loose connections, dirt or corrosion. Repair as necessary. Measure resistance between harness connector terminals No. 3 and 13. Reading should be between 3-6 ohms. If reading is not as specified, replace HCU. If readings are as specified, go to next step.
Measure resistance from HCU terminal No. 3 to housing. Reading should be greater than 10 megohms. If reading is not as specified, replace HCU. If reading is as specified, go to next step.
Measure resistance from HCU harness connector terminal No. 3 to vehicle chassis. See Figure . Reading should be greater than 10 megohms. If reading is not as specified, check Blue/White wire for a short to ground. If no open or short exists, go to next step.
Reconnect all connectors. Erase diagnostic trouble codes. See ERASING CODES under RETRIEVING CODES . If diagnostic trouble code 1-2-1-3 is still present, replace ABS control unit and repeat TEST G. If trouble code is intermittent, see TROUBLE SHOOTING .