1996 Mazda B-Series

TESTS W/CODES - 1996
1. 2) Check Electrical Signal Operation Disconnect transmission harness connector. Inspect condition of connector and repair as needed. Using DVOM (20-volt scale), connect positive lead to transmission vehicle harness connector terminal No. 11 (VPWR). See Figure. Connect negative lead to terminal No. 12 (EPC). Depress and release throttle to cycle solenoid output. If voltage changes at least .5 volts, go to step 5). If voltage is unaffected, go to next step.
2. 3) Check Continuity Of Solenoid Signal & VPWR Harness Circuits Ensure ignition is off. Disconnect PCM connector, and inspect it for damaged pins, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. On 1995 Explorer models, measure and record resistance between test pins No. 37 and 57 and transmission harness connector terminal No. 11 (VPWR). Measure and record resistance between breakout box test pin No. 38 and transmission harness connector terminal No. 12 (EPC). See Figure. On all other models, measure and record resistance between test pins No. 71 and 97 and transmission harness connector terminal No. 11 (VPWR). Measure and record resistance between breakout box test pin No. 81 and transmission harness connector terminal No. 12 (EPC). If any resistance is greater than 5 ohms, repair open circuit. Connect all components. Disconnect breakout box and repeat QUICK TEST. If each resistance is 5 ohms or less, go to next step.
3. 4) Check Solenoid/Harness For Shorts To Power & Ground On 1995 Explorer models, measure and record resistance between test pin No. 38 and test pins No. 37 and 57. Measure and record resistance between test pin No. 38 and test pins No. 40, 46 and 60. On all other models, measure and record resistance between breakout box test pin No. 81 and test pins No. 71 and 97. Measure and record resistance between test pin No. 81 and test pins No. 77, 91 and 103. If any resistance is less than 10 k/ohms, repair short circuit. Connect all components. Disconnect breakout box and repeat QUICK TEST. If each resistance is 10 k/ohms or more, go to next step.
4. 5) Solenoid Functional Test Connect transmission tester. Connect line pressure gauge. See AUTO TRANS OVERHAUL - FORD 4R44E & 4R55E article. Perform EPC solenoid functional test. See tester instructions. Observe line pressure on gauge while depressing EPC switch with KOER. EPC solenoid should activate (Green LED) and line pressure should drop when EPC switch is depressed. If solenoid operates correctly, replace PCM. Check power relay for damage or corrosion. Repair as necessary. Connect all components. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST. If solenoid is not operating, go to next step.
5. 6) Check Resistance Of Solenoid/Harness Set tester Bench/Drive switch to BENCH mode. Set Gear Selector switch to OHMS CHECK. Connect ohmmeter negative lead to EPC jack and positive lead to VPWR jack on tester. Measure resistance. Resistance should be 3.1-5.7 ohms. If resistance is within specification, go to next step. If resistance is not within specification, go to step 8).
6. 7) Check Solenoid/Harness For Short To Ground Check continuity between BAT (-) tester terminal and EPC terminals. If continuity exists, go to next step. Erase all trouble codes and road test vehicle. Repeat QUICK TEST. If continuity does not exist, see TROUBLE SHOOTING in AUTO TRANS OVERHAUL - FORD 4R44E & 4R55E article for non-electronic symptom diagnostics.
7. 8) Internal Electronic Diagnostics Drain transmission fluid. See TRANSMISSION SERVICING section. Remove transmission fluid pan. See VALVE BODY under ON-VEHICLE SERVICE in AUTO TRANS OVERHAUL - FORD 4R44E & 4R55E article. Inspect EPC internal harness connector. Ensure connector is fully connected and not damaged. Repair as needed. Install all components in reverse order of disassembly. Fill transmission with fluid. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST. If all connectors are okay, go to next step.
8. 9) Check Internal Harness Continuity Disconnect internal harness from EPC solenoid. Connect positive lead of ohmmeter to tester EPC jack and negative lead to EPC connector Blue wire. Measure and record resistance. Connect positive lead of ohmmeter to tester VPWR jack and negative lead to EPC connector Green wire. If each resistance is .5 ohms or less, go to next step. If any resistance is more than .5 ohms, replace internal harness.
9. 10) Check Internal Harness For Shorts To Ground Using transmission tester, check continuity between each EPC solenoid connector terminal and BAT (-) terminal of tester. If continuity does not exist in either circuit, go to next step. If continuity exists in any circuit, replace internal harness. Go to next step.
10. 11) Check Solenoid Resistance Using ohmmeter, check resistance between EPC solenoid terminals. If resistance is 3.1-5.7 ohms, go to next step. If resistance measured is not within specification, replace EPC solenoid. Install all components in reverse order of disassembly. Fill transmission with fluid. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST.
11. 12) Check Solenoid For Short To Ground Using ohmmeter, check continuity between each EPC solenoid terminal and ground. If continuity exists, replace faulty EPC solenoid. Install all components in reverse order of disassembly. Fill transmission with fluid. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST. If continuity does not exist, go to next step.
12. 13) Check Solenoid For Short To Power Using ohmmeter, check continuity between each EPC solenoid terminal and BAT (+) terminal of tester. If continuity exists, replace faulty EPC solenoid. Install all components in reverse order of disassembly. Fill transmission with fluid. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST. If continuity does not exist, install all components in reverse order of disassembly. Fill transmission with fluid. Erase all trouble codes. See CLEARING CODES. Repeat QUICK TEST. See TROUBLE SHOOTING in AUTO TRANS OVERHAUL - FORD 4R44E & 4R55E article for non-electronic symptom diagnostics.