Module Communications Network: Diagnosis Ford Explorer II

INSPECTION & VERIFICATION

1. Verify customer's original problem by operating system in question. Inspect vehicle for any obvious electrical component wiring or connector damage. Inspect connectors for loose, damaged or corroded terminals. Check related fuses for system in question.
2. Inspect 16-pin Data Link Connector (DLC) pins for damage. (Scheme 1) The DLC is located below driver's side of instrument panel, to the right of steering column. If pins are okay, go to next step. If pins are damaged, repair as necessary and proceed to next step.
3. If problem is still present after performing inspection, connect New Generation Star (NGS) tester to DLC. Select vehicle to be tested from NGS tester menu. If NGS tester does not communicate with vehicle, ensure program card is properly installed. Check NGS tester cable connections and ensure ignition is on. If NGS tester still does not communicate with vehicle, go to TEST M: NO MODULE/NETWORK COMMUNICATION under TESTING. If NGS tester communicates with vehicle, perform data link diagnostic procedure. See DATA LINK DIAGNOSTIC TEST.

Scheme 1

DATA LINK DIAGNOSTIC TEST

1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC), if not already connected. Select vehicle to be tested from NGS tester menu.
2. Turn ignition on. 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) for the module communications network and the ISO 9141 communication link (circuit No. 70). This is the Light Blue/White wire that is between terminal No. 7 on DLC and the air bag diagnostic monitor and other optional modules.
3. 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. Return to article that directed you here and continue diagnosis.
4. 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, go to TEST M: NO MODULE/NETWORK COMMUNICATION under TESTING. If NGS tester displays CKT 70, CKT 914 and/or CKT 915 = SOME ECUS NO RESP/NOT EQUIP, go to SYMPTOM INDEX table to continue diagnosis. If NGS tester displays CKT 70 = ALL ECUS NO RESP/NOT EQUIP, go to TEST K: NO MODULE/NETWORK COMMUNICATION - ISO 9141 LINK under TESTING. If NGS tester displays CKT 914 = ALL ECUS NO RESP/NOT EQUIP, go to TEST L: : NO MODULE/NETWORK COMMUNICATION - BUS LINK under TESTING. If NGS tester displays CKT 915 = ALL ECUS NO RESP/NOT EQUIP, go to TEST L: NO MODULE/NETWORK COMMUNICATION - BUS LINK under TESTING. If module in question is NO RESPONSE/NOT EQUIPPED, go to SYMPTOM INDEX table to continue diagnosis. If module in question is NO RESPONSE ON CKT 914 (BUS +), go to SYMPTOM INDEX table to continue diagnosis. If module in question is NO RESPONSE ON CKT 915 (BUS -), go to SYMPTOM INDEX table to continue diagnosis.

SYMPTOM TESTING

SYMPTOM INDEX

TESTING

Note. Always check module power and ground circuits prior to replacing a control module. See appropriate in DATA LINK CONNECTORS, GROUND DISTRIBUTION or POWER DISTRIBUTION wiring diagram in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.

TEST A: 4-WHEEL ANTI-LOCK BRAKE SYSTEM (4WABS) MODULE DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect 4WABS module connector located at left front of engine compartment. Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 20 at 4WABS module connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 1)and (Scheme 2). If resistance is less than 5 ohms, replace 4WABS module and retest system for normal operation. If resistance is 5 ohms or more, go to next step.
3. Disconnect and inspect both halves of 40-pin bulkhead connector C148 located at left rear of engine compartment, near brake master cylinder. (Scheme 3) Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
4. Measure resistance of Light Blue/White wire between terminal No. 16 at female half of connector C148 and terminal No. 7 at DLC. (Scheme 1)and (Scheme 4). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Light Blue/White wire between DLC and bulkhead connector. Retest system for normal operation.
5. Disconnect and inspect both halves in-line connector C140 located at left front of engine compartment, near 4WABS module connector. Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
6. Measure resistance of Light Blue/White wire between terminal No. 16 at male half of bulkhead connector C148 and terminal No. 7 at female half of in-line connector C140. (Scheme 4)and (Scheme 5).. If resistance is less than 5 ohms, repair open in Light Blue/White wire between in-line connector C140 and 4WABS connector. Retest system for normal operation. If resistance is 5 ohms or more, repair open in Light Blue/White wire between connector C148 and in-line connector C140. Retest system for normal operation.

Scheme 2

Scheme 3

Scheme 4

Scheme 5

TEST B: GENERIC ELECTRONIC MODULE (GEM)/CENTRAL TIMER MODULE (CTM) DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect GEM/CTM 26-pin connector C280 located behind center of instrument panel. (Scheme 3) Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 25 at GEM/CTM connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 1)and (Scheme 6). If resistance is less than 5 ohms, replace GEM/CTM and retest system for normal operation. If resistance is 5 ohms or more, repair open in Light Blue/White wire between GEM/CTM connector and DLC. Retest system for normal operation.

Scheme 6

TEST C: AIR BAG DIAGNOSTIC MONITOR DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Deactivate air bag system. See appropriate AIR BAG RESTRAINT SYSTEM article. Disconnect air bag diagnostic monitor Black connector C233 located behind right side of instrument panel. (Scheme 3) Inspect air bag diagnostic monitor connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 12 at air bag diagnostic monitor Black connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 1)and (Scheme 7). If resistance is less than 5 ohms, replace air bag diagnostic monitor and retest system for normal operation. If resistance is 5 ohms or more, repair open in Light Blue/White wire between air bag diagnostic monitor connector and DLC. Retest system for normal operation.

Scheme 7

TEST D: REMOTE ANTI-THEFT PERSONALITY (RAP) MODULE DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect RAP module 26-pin Gray connector C336 located behind left rear quarter panel. Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 3 at RAP module 26-pin connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 1)and (Scheme 5). If resistance is less than 5 ohms, replace RAP module and retest system for normal operation. If resistance is 5 ohms or more, go to next step.
3. Disconnect and inspect both halves of bulkhead connector C212 located at left corner of instrument panel, near cowl panel grommet. (Scheme 3) Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
4. Measure resistance of Light Blue/White wire between terminal No. 3 at RAP module 26-pin connector and terminal No. 51 at male half of bulkhead connector C212. (Scheme 8) If resistance is less than 5 ohms, repair open in Light Blue/White wire between female half of bulkhead connector C212 and DLC. Retest system for normal operation. If resistance is 5 ohms or more, repair open in Light Blue/White wire between RAP module 26-pin connector and male half of bulkhead connector C212. Retest system for normal operation.

Scheme 8

TEST E: POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO NGS TESTER

Note. If test results indicate PCM is faulty, always check for any engine performance related Diagnostic Trouble Codes (DTCs) prior to replacing PCM. If any DTCs are present, service DTCs as necessary and retest. See appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.

Scheme 9

1. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector C202 located in engine compartment, at right side of firewall. Inspect PCM connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Tan/Orange wire between terminal No. 16 at PCM connector and terminal No. 2 at Data Link Connector (DLC) (Scheme 1)and (Scheme 9). Also, measure resistance of Pink/Light Blue wire between terminal No. 15 at PCM connector and terminal No. 10 at DLC. If both resistance readings are less than 5 ohms, replace PCM and retest system for normal operation. If any resistance reading is 5 ohms or more, go to next step.
3. Disconnect and inspect both halves of 40-pin bulkhead connector C147 located at left rear corner engine compartment. (Scheme 3) Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
4. Measure resistance of Tan/Orange wire between terminal No. 21 at female half of bulkhead connector C147 and terminal No. 2 at DLC. (Scheme 1)and (Scheme 4). Also, measure resistance of Pink/Light Blue wire between terminal No. 25 at female half of bulkhead connector C147 and terminal No. 10 at DLC. If both resistance readings are less than 5 ohms, go to next step. If any resistance reading is 5 ohms or more, repair Tan/Orange wire and/or Pink/Light Blue wire between female half of bulkhead connector C147 and DLC. Retest system for normal operation.
5. Disconnect and inspect both halves of 42-pin bulkhead Gray connector C115. Connector is located at left rear corner engine compartment, right of brake booster. Inspect connector for physical damage, bent terminals or corrosion. (Scheme 10)Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
6. Measure resistance of Tan/Orange wire between terminal No. 21 at male half of bulkhead connector C147 and terminal No. 11 at male half of bulkhead connector C115. (Scheme 4)and (Scheme 10). Also, measure resistance of Pink/Light Blue wire between terminal No. 25 at male half of bulkhead connector C147 and terminal No. 3 at male half of bulkhead connector C115. If both resistance readings are less than 5 ohms, repair Tan/Orange wire and/or Pink/Light Blue wire between female half of bulkhead connector C115 and PCM connector. Retest system for normal operation. If any resistance reading is 5 ohms or more, repair Tan/Orange wire and/or Pink/Light Blue wire between male half of bulkhead connector C147 and bulkhead connector C115.

Scheme 10

TEST F: AIR RIDE CONTROL (ARC) MODULE DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect Air Ride Control (ARC) module Gray connector C2000 located left center of instrument panel. (Scheme 3) Inspect ARC module connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 29 at ARC module connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 11). If resistance is less than 5 ohms, replace ARC module and retest system for normal operation. If resistance 5 ohms or more, repair open in Light Blue/White wire between ARC module connector and DLC. Retest system for normal operation.

Scheme 11

TEST G: AUTOMATIC TEMPERATURE CONTROL (EATC) MODULE DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect Automatic Temperature Control (EATC) module Black connector C297 located left center of instrument panel. (Scheme 3) Inspect ARC module connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Tan/Orange wire between terminal No. 15 at EATC module connector and terminal No. 2 at Data Link Connector (DLC). (Scheme 1)and (Scheme 12).. Also, measure resistance of Light Blue/White wire between terminal No. 1 at EATC module connector and terminal No. 10 at DLC. If both resistance readings are less than 5 ohms, replace EATC module and retest system for normal operation. If any resistance reading is 5 ohms or more, repair Tan/Orange wire and/or Pink/Light Blue wire between DLC and EATC. Retest system for normal operation.

Scheme 12

TEST H: DRIVER SEAT MODULE (DSM) DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect Driver Seat Module (DSM) 22-pin connector C337 located under driver's seat. Inspect DSM connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Light Blue/White wire between terminal No. 22 at DSM connector and terminal No. 7 at Data Link Connector (DLC). (Scheme 1)and (Scheme 13). If resistance is less than 5 ohms, replace DSM and retest system for normal operation. If resistance is 5 ohms or more, go to next step.
3. Disconnect in-line connector C346 located under of driver's seat, toward rear of seat. Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
4. Measure resistance of Light Blue/White wire between terminal No. 22 at DSM connector C337 and terminal No. 11 at in-line connector C346. (Scheme 13)and (Scheme 14). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Light Blue/White wire between DSM connector C337 and in-line connector C346. Retest system for normal operation.
5. Disconnect and inspect both halves of bulkhead connector C212 located at left corner of instrument panel, near cowl panel grommet. (Scheme 3) Inspect connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
6. Measure resistance of Light Blue/White wire between terminal No. 7 at DLC and terminal No. 51 at male half of bulkhead connector C212. (Scheme 1)and (Scheme 8). If resistance is less than 5 ohms, repair open in Light Blue/White wire between male half of bulkhead connector C212 and in-line connector C346. Retest system for normal operation. If resistance is 5 ohms or more, repair open in Light Blue/White wire between female half of bulkhead connector C212 and DLC. Retest system for normal operation.

Scheme 13

Scheme 14

TEST J: PASSIVE ANTI-THEFT SYSTEM (PATS) MODULE DOES NOT RESPOND TO NGS TESTER

1. Turn ignition off. Disconnect PATS module 16-pin connector C222 located behind center of instrument panel. (Scheme 3) Inspect PATS module connector for physical damage, bent terminals or corrosion. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Measure resistance of Tan/Orange wire between terminal No. 6 at PATS module connector and terminal No. 2 at DLC. (Scheme 1)and (Scheme 15). Also, measure resistance of Pink/Light Blue wire between terminal No. 5 at PATS module connector and terminal No. 10 at DLC. If both resistance readings are less than 5 ohms, replace PATS module and retest system for normal operation. If any resistance reading is 5 ohms or more, repair Tan/Orange wire and/or Pink/Light Blue wire between DLC and PATS module. Retest system for normal operation.

Scheme 15

TEST K: NO MODULE/NETWORK COMMUNICATIONS - ISO 9141 LINK

1. Inspect NGS tester connector for loose, damaged or corroded terminals. Pay particular attention to terminal No. 7. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Turn ignition off. Inspect Data Link Connector (DLC) for physical damage, bent terminals or corrosion. Pay particular attention to terminal No. 7 (Light Blue/White wire). Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
3. Ensure ignition is off. Disconnect GEM/CTM 26-pin connector C280 located behind center of instrument panel. (Scheme 3) Measure resistance of Light Blue/White wire between terminal No. 25 at GEM/CTM 26-pin connector and terminal No. 7 at DLC. (Scheme 1)and (Scheme 6). If resistance is 5 ohms or more, repair open Light Blue/White wire between DLC and GEM/CTM connector. Retest system for normal operation. If resistance is less than 5 ohms, go to next step.
4. If vehicle is equipped with a Remote Anti-Theft Personality (RAP) module or a Driver Seat Module (DSM), go to next step. If vehicle is not equipped with a RAP module or a DSM, go to step 6).
5. Disconnect 84-pin in-line connector C212 located at left corner of instrument panel, near cowl panel grommet. (Scheme 3) Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, proceed as follows: If vehicle is equipped with a RAP module and a DSM, go to step 11). If vehicle is equipped with a RAP module only, go to step 14). If vehicle is equipped with a DSM only, go to step 15).
6. Turn ignition off. Reconnect in-line connector C212. Disconnect 40-pin bulkhead connector C148 located at left rear of engine compartment, near brake master cylinder. (Scheme 3) Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, go to step 17).
7. Turn ignition off. Reconnect bulkhead connector C148. If vehicle is equipped with a Automatic Ride Control (ARC) module, go to next step. If vehicle is not equipped with a ARC module, go to step 9).
8. Disconnect ARC module Gray connector C2000 located left center of instrument panel. (Scheme 3) Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace ARC and retest system for normal operation.
9. Turn ignition off. Reconnect ARC module connector C2000. Disconnect GEM/CTM 26-pin connector C280 located behind center of instrument panel. (Scheme 3) Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace GEM/CTM and retest system for normal operation.
10. Turn ignition off. Reconnect GEM/CTM 26-pin connector C280. Deactivate air bag system. See appropriate AIR BAG RESTRAINT SYSTEM article. Disconnect air bag diagnostic monitor connector. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, repair circuit No. 70 (Light Blue/White wire). Retest system for normal operation. If both readings indicate zero volts, replace air bag diagnostic monitor and retest system for normal operation.
11. Turn ignition off. Reconnect in-line connector C212. Disconnect RAP module 26-pin Gray connector C336 located behind left rear quarter panel. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace RAP module and retest system for normal operation.
12. Turn ignition off. Disconnect DSM 22-pin connector C337 located under driver's seat. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace DSM and retest system for normal operation.
13. Turn ignition off. Reconnect DSM connector C337. Disconnect in-line connector C346 located under of driver's seat, toward rear of seat. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, repair circuit No. 70 (Light Blue/White wire) between in-line connector C212, in-line connector C346 and RAP module connector. Retest system for normal operation. If both readings indicate zero volts, repair circuit No. 70 (Light Blue/White wire) between in-line connector C346 and DSM connector. Retest system for normal operation.
14. Turn ignition off. Reconnect in-line connector C212. Disconnect RAP module 26-pin Gray connector C336 located behind left rear quarter panel. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, repair circuit No. 70 (Light Blue/White wire) between in-line connector C212 and RAP module connector. Retest system for normal operation. If both readings indicate zero volts, replace RAP module and retest system for normal operation.
15. Turn ignition off. Reconnect in-line connector C212. Disconnect DSM 22-pin connector C337 located under driver's seat. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace DSM and retest system for normal operation.
16. Turn ignition off. Disconnect in-line connector C346 located under of driver's seat, toward rear of seat. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, repair circuit No. 70 (Light Blue/White wire) between in-line connector C212 and in-line connector C346. Retest system for normal operation. If both readings indicate zero volts, repair circuit No. 70 (Light Blue/White wire) between in-line connector C346 and DSM connector. Retest system for normal operation.
17. Turn ignition off. Reconnect 40-pin bulkhead connector C148. Disconnect 4WABS module connector located at left front of engine compartment. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, go to next step. If both readings indicate zero volts, replace 4WABS module and retest system for normal operation.
18. Turn ignition off. Disconnect in-line connector C140 located at left front of engine compartment, near 4WABS module connector. Turn ignition on. Measure voltage between terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire) at DLC. (Scheme 1) Also, measure voltage between terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire) at DLC. If any reading indicates voltage, repair circuit No. 70 (Light Blue/White wire) between in-line connector C148 and in-line connector C140. Retest system for normal operation. If both readings indicate zero volts, repair circuit No. 70 (Light Blue/White wire) between in-line connector C140 and 4WABS. Retest system for normal operation.

TEST L: NO MODULE/NETWORK COMMUNICATIONS - BUS LINK

1. Inspect NGS tester connector for physical damage, bent terminals or corrosion. Pay particular attention to terminals No. 2 and 10. Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Turn ignition off. Inspect Data Link Connector (DLC) for physical damage, bent terminals or corrosion. Pay particular attention to terminals No. 2 (Tan/Orange wire) and No. 10 (Pink/Light Blue wire). (Scheme 1) Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
3. Disconnect PATS module 16-pin connector C222 located behind center of instrument panel. (Scheme 3) Measure resistance of Tan/Orange wire between terminal No. 6 at PATS module connector and terminal No. 2 at DLC. (Scheme 1)and (Scheme 15). Also, measure resistance of Pink/Light Blue wire between terminal No. 5 at PATS module connector and terminal No. 10 at DLC. If both resistance readings are less than 5 ohms, go to next step. If any resistance reading is 5 ohms or more, repair Tan/Orange wire and/or Pink/Light Blue wire between DLC and PATS module. Retest system for normal operation.
4. Turn ignition on. Measure voltage between the following DLC terminals: Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 4 (Black wire) at DLC. (Scheme 1) Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 16 (Orange wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 4 (Black wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 16 (Orange wire) at DLC. If any reading indicates voltage, go to next step. If all readings indicate zero volts, replace PATS module. Retest system for normal operation.
5. Turn ignition off. Reconnect PATS module 16-pin connector C222. Disconnect Powertrain Control Module (PCM) connector C202 located in engine compartment, at right side of firewall. Turn ignition on. Measure voltage between the following DLC terminals: Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 4 (Black wire) at DLC. (Scheme 1) Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 16 (Orange wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 4 (Black wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 16 (Orange wire) at DLC. If any reading indicates voltage, on vehicles not equipped with Electronic Automatic Temperature Control (EATC), go to step 7). On vehicles equipped with EATC, go to next step. If all readings indicate zero volts, replace PCM. Retest system for normal operation.
6. Turn ignition off. Disconnect module Black connector C297 located left center of instrument panel. (Scheme 3) Measure voltage between the following DLC terminals: Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 4 (Black wire) at DLC. (Scheme 1) Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 16 (Orange wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 4 (Black wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 16 (Orange wire) at DLC. If any reading indicates voltage, go to next step. If all readings indicate zero volts, replace EATC module. Retest system for normal operation.
7. Turn ignition off. Disconnect 40-pin bulkhead connector C147 located at left rear corner engine compartment. (Scheme 3) Turn ignition on. Measure voltage between the following DLC terminals: Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 4 (Black wire) at DLC. (Scheme 1) Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 16 (Orange wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 4 (Black wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 16 (Orange wire) at DLC. If all readings indicate zero volts, go to next step. If any reading indicates voltage, repair Tan/Orange wire and/or Pink/Light Blue wire between bulkhead connector C147, DLC, PATS module and EATC. Retest system for normal operation.
8. Turn ignition off. Reconnect bulkhead connector C147. Disconnect 42-pin bulkhead Gray connector C115. Connector is located at left rear corner engine compartment, right of brake booster.Turn ignition on. Measure voltage between the following DLC terminals: Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 4 (Black wire) at DLC. (Scheme 1) Measure voltage between terminals No. 2 (Tan/Orange wire) and No. 16 (Orange wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 4 (Black wire) at DLC. Measure voltage between terminals No. 10 (Pink/Light Blue wire) and No. 16 (Orange wire) at DLC. If all readings indicate zero volts, repair Tan/Orange wire and/or Pink/Light Blue wire between bulkhead connector C115 and PCM. Retest system for normal operation. If any reading indicates voltage, repair Tan/Orange wire and/or Pink/Light Blue wire between bulkhead connector C147 and connector C115. Retest system for normal operation.

TEST M: NO MODULE/NETWORK COMMUNICATION

1. Inspect NGS tester connector for loose, damaged or corroded terminals. Repair as necessary and retest system for normal operation. If connector is okay, go to next step.
2. Turn ignition off. Inspect Data Link Connector (DLC) for physical damage, bent terminals or corrosion. Repair as necessary and retest system for normal operation. If connector is okay, go to next step.
3. Turn ignition off. Remove and inspect fuse No. 5 (10-amp) from instrument panel fuse block. If fuse is blown, go to next step. If fuse is okay, reinstall fuse and go to step 5).
4. Replace fuse and retest system for normal operation. Recheck fuse. If fuse is okay, go to next step. If fuse is blown, repair short to ground in circuit No. 693 (Orange wire) between instrument panel fuse block and DLC. Retest system for normal operation.
5. Measure voltage between ground and terminal No. 16 (Orange wire) at DLC. (Scheme 1) If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair circuit No. 693 (Orange wire) between instrument panel fuse block and DLC. Retest system for normal operation.
6. Measure resistance between ground and terminals No. 4 (Black wire) and No. 5 (Black/White wire) at DLC. If both resistance readings are less than 5 ohms, repair or replace NGS tester. Retest system for normal operation. If any resistance reading is 5 ohms or more, repair open in Black wire or Black/White wire between ground and DLC. Retest system for normal operation.