1994 MAZDA MX-5 engine

K TROUBLESHOOTING TROUBLESHOOTING GENERAL NOTES A problem with the EC-AT may be caused by the engine, the EC-AT powertrain, the hydraulic control LJ system, or the electronic control system. When troubleshooting, therefore, begin from these points, which can be inspected quickly and easily. The recommended troubleshooting sequence is described below. WHEEL CHOCK 63 TEMPERATURE w-7u'C (1461WF) Step 1 : On-board Diagnosis System Inspection Check for diagnostic trouble code(s) memorized in the powertrain control module (Transmission) with the Self- Diagnosis Checker. (Refer to page K-11 .) Note You can also check the flashing sequence of the hold indicator light for diagnostic trouble code(s). (Refer to page K-1 1 .) Step 2: Mechanical System Test Check the engine stall speed, time lag, and line pres- sure. (Refer to page K-22.) Step 3: Road Test Check the shift point, shift schedule, and shift shock. (Refer to page K-29.) Gartner Banana

TROUBLESHOOTING If the 3 steps on page K-8 are followed, the cause of the problem should be located. Another guide to faster location of the causes of problems, the QUICK DIAGNOSIS CHART, is on page K-1 0. b In this chart, numbers are used to indicate the components that may be the cause of 22 possible prob- lems. It is necessary to check only those components indicated by numbers during each step of the trouble- shooting process to locate the cause of the problem quickly. QUICK DIAGNOSIS CHART The QUICK DIAGNOSIS CHART shows different .problems and the relationship of components that might be the cause. 1. Components indicated in the "Adjustment" row indicate the possibility that the problem may result from an incorrect adjustment. Check the adjustment of each component, and readjust if necessary. 2. Components indicated in the "Self-DiagnosisWrow are diagnosed by the Powertrain control module (Transmission) self-diagnostic function. 3. Input and output signals of the Powertrain control module (Transmission) for components indicated in the "Tester" row can be easily checked with the Engine signal Monitor. 4. Components indicated in the "Mechanical System Test" row can be checked for malfunction by the re- sults of oil pressure test. 5. Components indicated in the "Road Test" row can be checked for malfunction by the results of the road test. 6. The numbers in the chart indicate the order of inspection for detecting malfunctions. 7. Circled numbers indicate that the transmission must be removed from the vehicle. 8. The checking, adjusting, repair, and replacement procedures for components are described in the page(s) shown in the "Reference page" row. Gartner Banana

K TROUBLESHOOTING Hydraulic Electronic control Prelimi- control Powertrain system "8' svstem rieference page I I \dd I Vehicle does not move in D, S, L, or R range iccelerating Vehicle moves in N range Excessive creep Not creep at all No shift 0 0 Abnormal shift sequence 0 0 Frequent shifting 0 Shifting Excessivelv hiah or low shift point 0 0 . - No lockup I No kickdown l0k I - 1 Engine runaway or slip when \,I starting vehicle- V Slipping Engine runaway or slip when up- I I I or downshifting I I ] Excessive N to D or N to R shift 1,1 shock w I change in range I Transmission noisy in N or P Noise range Transmission noisy in D, S, L, or I 1 I R ranae I I Other .. - - ( No engine braking I Transmission overheats I I White smoke discharged from exhaust Engine will not start 10 1 Gartner Banana

ON-BOARD DIAGNOSIS SYSTEM K :TIC TROUBLE CODE No.55 VEHICLE SPEED PULSE GENERATOR ACTION Repair or replace connector INSPECTION control module (transmission) connector or terminal? I (+) term. 1 (-) term. I Voltage (v)( Condition I Are there any poor connections at vehicle speed pulse generator and powertrain No ' Go to next step Connect a circuit tester to terminal as shown Is input voltage of vehicle speed pulse generator at powertrain control module (transmission) OK? page K45 Engine Yes Engine I o ( stopped ( Yes Disconnect 20-pin powertrain control module (transmission) connector Is resistance between terminal 2J and ter- minal 2L OK? Go to step 5 I No I Go to next step Yes Go to step 5 Resistance: 200--400a Disconnect vehicle speed pulse genera- tor connector Is resistance between terminal E and ter- minal F OK? page K41 Resistance: 200--400n Disconnect the negative battery cable for at least 20 seconds and depress the brake mdal Sonnect the battery cable and recheck for jiagnostic trouble code Is diagnostic trouble code displayed? page K-21 45UOKX-019 Yes No Yes No Check wiring and connectors form powertrain control module (transmission) vehicle speed pules generator If OK, go to next step If not OK, repair wiring and/or connector Replace pulse generator Replace powertrain control module (transmission) us page K-45 Intermittent poor connection Check for cause Gartner Banana

K MECHANICAL SYSTEM TEST MECHANICAL SYSTEM TEST PREPARATION SST STALL TEST 49 0378 400A Gauge set, oil pressure 49 801 9 901 Gauge, oil pressure For oil pressure test For oil pressure test This test is performed to determine if there is slippage of the friction elements or malfunction of the hy- draulic components. Preparation 1. Check the engine coolant, engine oil, and ATF levels before testing. 2. Warm the engine thoroughly to raise the ATF temperature to operating level (50--80°C, 122-176°F). 3. Engage the parking brake and use wheel chocks at the front and rear of the wheels. ENGAGE PARKING BRAKE WARM UP ENGINE COOLANT LEVEL ENGINE OIL LEVEL TEMPERATURE 60-70°C (1 40-1 58°F) ATF LEVEL Gartner Banana

MECHANICAL SYSTEM TEST K Procedure ENGAGE PARKING BRAKE IDLE SPEED 1. Connect a tachometer to the engine. 2. Start the engine and check the idle speed in P range. (Refer to section F.) Idle speed: 750-450 rpm 3. Shift the selector lever to R range. Caution If the accelerator pedal is pressed for longer than 5 seconds while the brake pedal is pressed, the transmission could be damaged. Therefore, do steps 4 and 5 within 5 seconds of each oth- er. 4. Firmly depress the foot brake with the left foot, and gently depress the accelerator pedal with the right. 5. When the engine speed no longer increases, quickly read the engine speed and release the accelerator. 6. Shift the selector to N and let the engine idle for 1 minute or more to cool the ATF. 7. Perform the stall test for the following ranges in the same manner. (1 ) D range u (2) S range (3) L range Engine stall speed: 1,90&2,lOO rpm Gartner Banana

K MECHANICAL SYSTEM TEST Evaluation of Stall Test 4bove specification Nithin specification In all ranges In D (Normal), and L ranges In D (Normal) range only In R range only 3elow specification Possible cause I Worn oil Dumo Oil leakage from oil pump, control Insufficient line pressure Direct clutch and overdrive one-way clutch sli~~ina Rear clutch slipping One-way clutch slipping Low and reverse brake slipping Front clutch slipping Perform road test to determine if this is caused by low and reverse brake or front clutch as follows: a) Effective engine braking in L range . . . . . . . . . . Front clutch b) No enaine brakina in L range . . . . . Low and reverse brake All ~hiftcont~elements within transmission are functioning normally Engine out of tune One-wav clutch sli~~ina within toraue converter Gartner Banana

MECHANICAL SYSTEM TEST TIME LAG TEST If the selector lever is shifted while the engine is idling, there will be a certain time lapse, or time lag, before shock is felt. This step checks this time lag for checking condition of the 1-2, N-R/2-3 and N-D L/ accumulators, front, rear and one-way clutches, 2nd brake band, and low and reverse brake. Preparation Perform the preparation procedure shown in the STALL TEST. (Refer to page K-22.) Procedure IDLE SPEED 1. Start the engine and check the idle speed in P range. (Refer to section F.) u Idle speed: 750--850 rpm 2. Shift from N range to D range. 3. Use a stopwatch to measure the time it takes from shifting until shock is felt. 4. Shift the selector to N and let the engine idle for 1 minute or more to cool the ATF. 5. Do the time lag test for the following shifts in the same manner. Make three measurements for each test and average the results. (1) N 4 D range (Normal mode) (2) N -+ D range (Hold mode) (3) N -+ R range .......................................... Specified time lag: N -t D range 0.5-46 second ..................... N -+ R range ... .............. 0.75-0.85 second Evaluation of Time Lag Test - I Condition N -c D (Hold) shifting More than specification Less than specification More than specification Less than specification N -+ R shifting I More than specification Less than specification Rear clutch slipping Excessive line pressure - lnsufficient line pressure Rear clutch slipping 2nd brake band slipping - 1-2 accumulator not operating properly Excessive line pressure lnsufficient line pressure Low and reverse brake slipping Front clutch slipping N-R/2-3 accumulator not operating properly Excessive line pressure K-25 Gartner Banana