Diagnosis - CD4E Automatic Transmission: Other Mazda 626 GF

Retrieving Codes

Fault codes are retrieved from EEC-V system through Data Link Connector (DLC). DLC is located below instrument panel, to right of steering wheel. Self-diagnostic test procedures are for use with New Generation Star (NGS) scan tool. If a generic scan tool is used, ensure tool is certified OBD-II standard and refer to scan tool manufacturers operating procedures.

KOEO & KOER Codes (Hard Faults)

These codes indicate faults are present at time of testing. A hard fault may cause CHECK ENGINE or Malfunction Indicator Light (MIL) to go on and remain on until fault is repaired. If KOEO or KOER codes are retrieved during KOEO SELF-TEST or KOER SELF-TEST, use DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION to find correct testing and repair procedures.

Continuous Memory Codes (Intermittent Faults)

These codes are used to diagnose intermittent problems. Continuous Memory codes are retrieved after KOEO SELF-TEST. These codes indicate a fault that may or may not be present at time of testing.

After noting and/or repairing fault, clear codes from memory. See CLEARING CODES . Intermittent faults may be caused by a sensor, connector or wiring-related problem.

Air Conditioning Clutch (ACC) Switch

On factory installed A/C system, PCM receives signal voltage from ACC switch indicating that the air conditioning compressor clutch is engaged. The PCM uses the ACC switch signal to adjust line pressure to compensate for additional engine load. If the ACC switch fails with closed contacts, line pressure will be slightly lower with air conditioning off. If the ACC switch fails with open contacts, line pressure will be slightly higher with air conditioning on.

Brake Pedal Position (BPP) Switch

The PCM receives a signal from the BPP switch when the brake switch is operated. BPP switch may also be known as Brake ON/Off (BOO) switch. Torque converter clutch is disengaged when brakes are applied. Malfunctioning switch will affect torque converter operation.

Crankshaft Position (CKP) Sensor & Ignition Control Module (ICM)

The CKP sensor sends crankshaft position information to the ICM, which sends an engine speed signal to the PCM. Signal received by the PCM affects line pressure, shift scheduling, torque converter clutch and WOT shift control. Engine speed signal malfunction may result in harsh engagements, firm shifts, TCC lock-up and/or late WOT shifts.

Engine Coolant Temperature (ECT) Sensor

Engine temperature signal is sent to PCM. Malfunctioning ECT sensor will affect torque converter clutch operation.

Mass Airflow (MAF) Sensor

The MAF signal is used for Electronic Pressure Control (EPC), shift and TCC operation. MAF sensor malfunction will affect these areas.

Output Shaft Speed (OSS) Sensor

OSS is a magnetic pick-up that detects park gear teeth (output shaft) rotational speed. Signal is sent to PCM and used for shift scheduling. Input is also used for electronic speedometer, trip computer, speed control and adaptive damping.

Transmission Control Switch (TCS)

Switch is mounted on shift lever handle. Switch controls operation of 4th gear. Malfunction of switch will cause lack of 4th gear disable function.

Throttle Position (TP) Sensor

The TP sensor is a potentiometer mounted to the engine throttle body. The PCM receives a signal from the TP sensor relaying throttle plate position. TP sensor failure will cause PCM to operate in fail safe mode and raise line pressure to prevent transaxle damage. This condition will result in harsh engagements, firm shift feel, abnormal shift schedule and TCC not engaging or cycling.

Transmission Range (TR) Sensor

The PCM monitors a series of step down resistors in the TR sensor that act as a voltage divider. The voltage signal corresponds with position of the transaxle selector lever. The TR sensor also contains the neutral/start and back-up light circuits. Malfunction of the TR sensor may cause harsh engagements and firm shift feel. Improper shifting or shift selection and no engine cranking may also result.

Turbine Shaft Speed (TSS) Sensor

The TSS sensor sensor is a magnetic pick-up that sends turbine shaft speed signal to the PCM. Malfunction of sensor may cause harsh engagements of shifts. Lack of 4th gear or no engine braking in 2nd or 3rd gear may result.

Vehicle Speed Sensor (VSS)

The VSS is a magnetic pick-up that sends output speed signal to the PCM. Malfunction of sensor may cause harsh engagements of shifts. Lack of 4th gear, TCC lock-up, or engine braking in 2nd or 3rd gear may result.

NO REVERSE ENGAGEMENT

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH ENGAGEMENT IN "R" OR "D" POSITIONS

Perform QUICK TEST and record DTCs. Perform TEST B and TEST E in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOME OR ALL SHIFTS MISSING

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOME OR ALL SHIFTS EARLY OR LATE

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

ERRATIC OR HUNTING SHIFTS

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST A , TEST C , TEST D , TEST F and TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOFT OR SLIPPING SHIFTS

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B and TEST E in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH SHIFTS

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E , TEST F and TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO 1ST GEAR IN "D" POSITION

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO 1ST GEAR IN "1" POSITION

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO 1-2 UPSHIFT in "D" POSITION

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO 2-3 UPSHIFT IN "D" POSITION

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO 3-4 UPSHIFT IN "D" POSITION

Perform QUICK TEST and record DTCs. Perform TEST A and TEST D in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOFT OR SLIPPING 1-2 SHIFT

Perform STALL SPEED TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B and TEST E in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOFT OR SLIPPING 2-3 SHIFT

Perform STALL SPEED TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B and TEST E in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

SOFT OR SLIPPING 3-4 SHIFT

Perform QUICK TEST and record DTCs. Perform TEST B and TEST E in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH 1-2 SHIFT

Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E and TEST F in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present. Perform STALL SPEED TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article.

HARSH 2-3 SHIFT

Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E , TEST F and TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH 3-4 SHIFT

Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E , TEST F and TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH 4-3 SHIFT

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E , TEST F and TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

HARSH 3-2 SHIFT

Perform QUICK TEST and record DTCs. Perform TEST B , TEST C , TEST D , TEST E and TEST F in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO TCC ENGAGEMENT

Perform ROAD TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST B , TEST C and TEST F in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

TCC ALWAYS ENGAGED

Perform QUICK TEST and record DTCs. Perform TEST B and TEST C in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

TRANSMISSION OVERHEATING

Perform QUICK TEST and record DTCs. Perform TEST B , TEST C and TEST F in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

NO ENGINE BRAKING WITH "OD" OFF (1ST & 2ND GEARS)

Perform STALL SPEED TEST in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Perform QUICK TEST and record DTCs. Perform TEST G in SYSTEM TESTS. Repair as necessary. Clear codes and perform TRANSMISSION DRIVE CYCLE TEST . Repeat QUICK TEST and ensure DTCs are not present.

Visual Check

Complete all steps in PRELIMINARY INSPECTION before proceeding to self-diagnostic tests. Ensure vacuum hoses and EEC-V wiring harnesses are properly connected.

Equipment Hookup

Apply parking brake, and place shift lever in Park position. Block drive wheels. Turn off all electrical accessories. Connect appropriate test equipment to vehicle as follows

Scheme 218

1. Generic Scan Tool Ensure scan tool meets or exceeds OBD-II standard. Follow manufacturer's instructions to hook up equipment and record diagnostic trouble codes.
2. New Generation STAR (NGS) Tester Turn ignition switch to OFF position. Connect adapter cable lead to diagnostic tester. (Scheme 218) Connect service connectors of adapter cable to vehicle Data Link Connector (DLC). Go to KOEO SELF-TEST.

READING CODES

Note. For engine related DTCs, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. These DTCs pertain to engine performance and must be repaired first, as engine performance and related component signals (TP sensor, VSS etc.) will affect transaxle operation and diagnosis.

Pass Codes

SYSTEM PASS indicates no diagnostic trouble codes were recorded in that portion of test. If SYSTEM PASS is not retrieved in KOEO SELF-TEST, codes retrieved during KOER SELF-TEST may not be valid.

Continuous Memory Codes

These codes result from information stored by PCM during continuous self-test monitoring. Use these codes for diagnosis only when KOEO SELF-TEST and KOER SELF-TEST result in SYSTEM PASS and all steps under QUICK TEST are successfully completed. These codes indicate faults previously recorded. Fault may or may not be currently present. See DTC IDENTIFICATION .

CLEARING CODES

ADDITIONAL SYSTEM FUNCTIONS

Note. Additional diagnostic system features are available to help diagnose driveability problems and service EEC-V systems.

Preliminary Set Up

Connect Transaxle Tester (007-0085D). Install pressure gauge to line pressure tap. See FORD CD4E (MAZDA LA4A-EL) OVERHAUL article. Set Bench/Drive switch to DRIVE mode. Set tester to Gear Select "1" position. Ensure vehicle is in "P" position. Start vehicle.

EPC Solenoid

Record line pressure. Maximum line pressure should be 76 psi (5.3 kg/cm 2 ). If line pressure is not within specification, see PERFORMANCE TESTS in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article or SYSTEM TEST E. Depress EPC switch. Minimum line pressure should be 64 psi (4.5 kg/cm 2 ). If line pressure is not within specification, see PERFORMANCE TESTS in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article or SYSTEM TEST E.

Engagements

1. Rotate Gear Select switch to 3/R position. Shift transaxle from Park to Reverse. Reverse should engage. Shift transaxle from Reverse to Park. Rotate Gear Select switch to "1" position. Depress EPC switch. Line pressure should drop to idle pressure (64 psi (4.5 kg/cm 2 ).
2. While depressing EPC switch, shift vehicle from Park to Drive. Vehicle should shift into Drive with smooth engagement. Release EPC switch and repeat previous step. Vehicle shift engagement should be firm with EPC switch released.

Note. Ensure Gear Select switch is in 3/R position for Reverse gear. Upshifts and downshifts will be firm during this procedure.

Upshift/Downshift

1. Remove pressure gauge. Set Gear Select switch to "1" position. Shift transaxle to Drive. Depress the 3-2T/CCS button and accelerate (road test) vehicle. If vehicle will not move, forward one-way clutch failure is possible. If vehicle moves, go to next step.
2. Ensure Gear Select switch is in "1" position. Shift transaxle to overdrive and accelerate to 15 MPH. Rotate Gear Select switch to "2" position. Vehicle should shift into 2nd gear. Accelerate to 25 MPH and select "3" position. Vehicle should shift into 3rd gear. Accelerate to 35-45 MPH and select "4" position. Vehicle should shift into 4th gear.
3. Downshift as outlined in step 2 . To prevent harsh 4-3 downshift, depress 3-2T/CCS switch during 4-3 downshift. Vehicle should downshift through each gear.

3-2 Timing/Coast Clutch Engagement

Accelerate and upshift vehicle into 3rd gear. Release throttle and depress 3-2T/CCS switch. Coast clutch should disengage. Lightly depress throttle and release 3-2T/CCS switch. Engine braking should occur.

Note. This test may be performed on hoist.

Turbine Speed Sensor Function Check

Set voltmeter to 20 volts A/C. Connect voltmeter leads to appropriate TSS sensor jacks. Slowly accelerate vehicle and monitor voltmeter reading. Voltage should increase with vehicle speed.

SYSTEM TESTS

Note. SYSTEM TESTS are diagnostic formats used to test and service EEC-V system. QUICK TEST allows technician to identify problems and retrieve service codes. CIRCUIT TESTS check engine circuits, sensors and actuators. SYSTEM TESTS check transaxle circuits, sensors and actuators.

Note. Procedures in SYSTEM TESTS are written for the use of the following Ford Motor Co. test equipment

1. New Generation Star (NGS) Tester (007-00500)
2. Breakout Box (014-00950)
3. Transmission Tester (007-0085D) terminal pin references are based on this equipment and appropriate overlays. All references to "test pins", "test terminals" or "jacks" refer to test equipment. When aftermarket test equipment is used, always follow test equipment manufacturers procedures.

HOW TO USE SYSTEM TESTS

1. DO NOT perform any SYSTEM TEST unless specifically instructed by a «QUICK TEST»(ref-129633-S17898111942001111500000) procedure. Follow each test step in order until fault is found. DO NOT replace any part unless directed to do so. When more than one code is retrieved, start with first code displayed.
2. SYSTEM TESTS ensure electrical circuits are okay before sensors or other components are replaced. Always test circuits for continuity between sensor and PCM. Test all circuits for short to power, opens or short to ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with ignition on or as specified in SYSTEM TESTS.
3. DO NOT measure voltage or resistance at PCM. DO NOT connect any test light unless specified in testing procedure. All measurements are made by probing rear of connector. Isolate both ends of a circuit and turn ignition off when checking for shorts or continuity, unless instructed otherwise.
4. Disconnect solenoids and switches from harness before measuring continuity and resistance or applying voltage. After each repair, check all component connections and repeat «QUICK TEST»(ref-129633-S17898111942001111500000) .
5. An open circuit is defined as a resistance reading of greater than 5 ohms. This specification tolerance may be too high for some items in EEC-V system. If resistance approaches 5 ohms, always clean suspect connector and coat it with protective dielectric silicone grease. A short is defined as a resistance reading of less than 10 k/ohms to ground, unless stated otherwise in SYSTEM TEST.

Scheme 219

1. Electronic Diagnostics Ensure transaxle harness connector is in acceptable condition. Repair as necessary. Ensure transaxle harness connector is fully seated. Connect NGS tester or equivalent to DLC. Perform KOEO test until Continuous Memory trouble code(s) have been displayed. See «QUICK TEST»(ref-129633-S17898111942001111500000). Enter output test mode. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-129633-S19547804582001111500000). Select ALL ON mode. Push START to turn outputs ON. Push STOP to turn outputs OFF. If vehicle enters output state, go to next step. If vehicle will not enter output state, see «SCAN TOOL UNABLE TO COMMUNICATE»(ref-129633-S28357830972000020900000).
2. Check Electrical Signal Operation Turn ignition off. Disconnect transaxle harness connector. Inspect condition of connector and repair as needed. Turn ignition on. Using DVOM, connect positive lead to transaxle harness connector terminal No. 5. (Scheme 219) Connect negative lead to suspect solenoid circuit. While monitoring DVOM, press START and STOP to cycle solenoid output on and off. If voltage changes at least.5 volt, go to step 5. If voltage is unaffected, go to next step.
3. Check Continuity Of Solenoid Signal & VPWR Harness Circuits Ensure ignition is off. Disconnect PCM 104-pin connector, and inspect it for damaged pins, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. Measure and record resistance between breakout box test pin No. 1 and transaxle harness connector terminal No. 6. (Scheme 219) Measure and record resistance between test pin No. 27 and transaxle harness connector terminal No. 4. Measure and record resistance between test pins No. 71 and 97 and transaxle harness connector terminal No. 5. If any resistance is greater than 5 ohms, repair open circuit. Connect all components. Disconnect breakout box and repeat «QUICK TEST»(ref-129633-S17898111942001111500000). If each resistance is 5 ohms or less, go to next step.
4. Check Solenoid Harness For Shorts To Power & Ground Measure and record resistance between breakout box test pins No. 1 or 27 and test pins No. 71 and 97. Measure and record resistance between chassis ground and test pin No. 1 or 27, and between chassis ground and test pins No. 24, 51, 76, 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»(ref-129633-S17898111942001111500000). If each resistance is 10 k/ohms or more, go to next step.
5. Solenoid Functional Test Connect transaxle tester. Perform solenoid voltage test. See tester instructions. If solenoid activates (Green LED on), go to next step. If solenoid does not activate LED, go to step 7.
6. Transaxle Drive Test Connect PCM 104-pin connector. Perform tester drive test. See tester instructions. If vehicle upshifts when operated with tester, replace PCM. Connect all components. Disconnect breakout box and repeat «QUICK TEST»(ref-129633-S17898111942001111500000). If vehicle does not upshift when operated by tester, go to next step.
7. Check Resistance Of Solenoid Set tester Bench/Drive switch to BENCH position. Set Solenoid Selector switch to OHMS CHECK. Connect ohmmeter negative lead to SS1 jack and positive lead to VPWR jack on tester. Measure and record resistance. Connect ohmmeter negative lead to SS2 jack and positive lead to VPWR jack on tester. Measure and record resistance. Resistance for both solenoids should be 12-22 ohms. If resistance is within specification, go to next step. If resistance is not within specification, replace solenoid body assembly. Erase all trouble codes. See «CLEARING CODES»(ref-129633-S11554415332001111500000). Repeat «QUICK TEST»(ref-129633-S17898111942001111500000).
8. Check Solenoid For Short To Ground Check continuity between BAT(-) terminal and between SS1 and SS2 jacks. If continuity exists, replace solenoid body assembly. Erase all trouble codes. See «CLEARING CODES»(ref-129633-S11554415332001111500000). Repeat «QUICK TEST»(ref-129633-S17898111942001111500000). If continuity does not exist, see TROUBLE SHOOTING in FORD CD4E (MAZDA LA4A-EL) OVERHAUL article for non-electronic symptom diagnostics.