Data Link Diagnostic Test

WARNING: This page is about a different car, the 1999 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Circuit No. 70 is the Light Blue/White wire connected to terminal No. 7 on DLC. Circuit No. 914 is the Tan/Orange wire connected to terminal No. 2 on DLC. Circuit No. 915 is the Pink/Light Blue wire connected to terminal No. 10 on DLC.

Connect New Generation Star (NGS) tester to Data Link Connector (DLC), if not already connected. Select vehicle to be tested from NGS tester menu.
Turn ignition switch to RUN position. Rotate dial on NGS tester to menu item DIAGNOSTIC DATA LINK and press trigger. A test will be performed on the BUS (circuits No. 914 and 915) network and the ISO 9141 network (circuit No. 70).
If NGS tester displays CKT 914 (+) = SYSTEM PASSED and CKT 915 (-) = SYSTEM PASSED, module communications network is okay. If NGS tester displays CKT 70 = SYSTEM PASSED, ISO 9141 communication link is operating properly. Repair communication concern by symptom. See SYMPTOM INDEX table to continue diagnosis.
If NGS tester does not display CKT 914 (+) = SYSTEM PASSED, CKT 915 (-) = SYSTEM PASSED and CKT 70 = SYSTEM PASSED, perform the following as applicable.
- If no response from NGS tester, perform TEST N: NO MODULE/NETWORK COMMUNICATION under SYSTEM TESTS.
- If NGS tester displays CKT 70, CKT 914 and/or CKT 915 = SOME ECUS NO RESP/NOT EQUIP, repair communication concern by symptom. See SYMPTOM INDEX table to continue diagnosis.
- If NGS tester displays CKT 70 = ALL ECUS NO RESP/NOT EQUIP, perform TEST F: RESTRAINT CONTROL MODULE (RCM) DOES NOT RESPOND TO NGS TESTER under SYSTEM TESTS.
- If NGS tester displays CKT 914 = ALL ECUS NO RESP/NOT EQUIP, perform TEST M: NO MODULE/NETWORK COMMUNICATION - BUS LINK under SYSTEM TESTS.
- If NGS tester displays CKT 915 = ALL ECUS NO RESP/NOT EQUIP, perform TEST M: NO MODULE/NETWORK COMMUNICATION - BUS LINK under SYSTEM TESTS.
- If module in question is NO RESPONSE/NOT EQUIPPED, repair communication concern by symptom. See SYMPTOM INDEX table to continue diagnosis.
- If module in question is NO RESPONSE ON CKT 914 (BUS +), repair communication concern by symptom. See SYMPTOM INDEX table to continue diagnosis.
- If module in question is NO RESPONSE ON CKT 915 (BUS -), repair communication concern by symptom. See SYMPTOM INDEX table to continue diagnosis.

SYMPTOM INDEX

Condition

Perform Test

Anti-Lock Brake System (ABS) Module Does Not Respond To NGS Tester

Front Radio Control Unit Does Not Respond To NGS Tester ⁽¹⁾

Driver's Door Module (DDM) Does Not Respond To NGS Tester

Driver's Seat Module (DSM) Does Not Respond To NGS Tester

Electronic Automatic Temperature Control (EATC) Module Does Not Respond To NGS Tester

Restraint Control Module (RCM) Does Not Respond To NGS Tester

Lighting Control Module (LCM) Does Not Respond To NGS Tester

Speed Control Servo Does Not Respond To NGS Tester ⁽²⁾

Powertrain Control Module (PCM) Does Not Respond To NGS Tester

Air Suspension/Electronic Variable Orifice (EVO) Steering Module Does Not Respond To NGS Tester ⁽³⁾

Instrument Cluster Does Not Respond To NGS Tester ⁽⁴⁾

No Module/Network Communication - ISO 9141 Network

No Module/Network Communication - SCP Bus Link

No Module/Network Communication - No Power To NGS Tester

⁽¹⁾	Front radio control unit may also be referred to as Audio Control Module (ACM).

⁽²⁾	Speed control servo may also be referred to as Next Generation Speed Control (NGSC) servo.

⁽³⁾	Air Suspension/Electronic Variable Orifice (EVO) steering module may also be referred to as Rear Air Suspension Module (RASM).

⁽⁴⁾	Instrument cluster may also be referred to as Hybrid Electronic Cluster (HEC).