5A
Transmission Warning Light Circuit Check – Light Does Not Come “ON” at Ignition Switch ON (M13A Model without VVT)
Wiring Diagram
1. TCM 4. Transmission warning light
2. Combination meter [A]: Terminal arrangement of TCM connector (M13 engine model without VVT) (viewed from harness side)
3. Light driver      
Circuit Description
When ignition switch is turned ON and malfunction is not detected, TCM turns transmission warning light ON only for 2 seconds to check bulb and turns it OFF.
When ignition switch is turned ON and malfunction is detected, regardless of whether engine is running or not, transmission warning light is turned ON by TCM and combination meter while malfunction is detected to warn driver of such occurrence of trouble. TCM-Combination meter signal which is outputted from TCM to combination meter is a voltage signal (0 – 12 volts) which is outputted from TCM to combination meter through the signal circuit, based on transmission warning light signal and A/T select lever position indicator signal.
Troubleshooting
Step Action YES NO
1
Combination Meter Power Supply Check
1) Turn ignition switch ON.
Does other indicator/warning lights in combination meter comes ON?
Go to Step 2.
Repair combination meter power supply circuit referring to Combination Meter Circuit Diagram .
2
TCM power and ground circuit check
Refer to TCM Power and Ground Circuit Check .
Is it in good condition?
Go to Step 3.
Repair or replace.
3
Combination Meter Function Check
1) Turn ignition switch ON.
Does A/T selector position indicator show correct select lever position?
Substitute a known-good combination meter and recheck.
Go to Step 4.
4
TCM-Combination Meter Serial Communication Circuit Check
1) Disconnect TCM connector.
2) Turn ignition switch ON.
3) Measure voltage between “E124-10” terminal of TCM connector and vehicle body ground.
Is voltage 12 – 15 V?
Go to Step 5.
Open or short to ground circuit in “YEL/BLK” circuit.
5
TCM-Combination Meter Serial Communication Circuit Check
1) Disconnect combination meter connector.
2) Turn ignition switch ON.
3) Measure voltage between “E124-10” terminal of TCM connector and vehicle body ground.
Is voltage 12 – 15 V?
Short to power circuit in “YEL/BLK” circuit.
Substitute a known-good TCM and recheck. If OK, substitute a known-good combination meter and recheck.