Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

When turning the ignition switch to the START position, check whether the starter motor operates. If engine starts, system is okay at this time. Check for intermittent problem. Check harness wires, connectors and terminals for damage and repair or replace as necessary. If starter does not operate when key is turned to START position, go to next step.
Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Backprobing and while cranking, measure voltage between ECM 32-pin connector E6 terminal No. 1 (-) and ECM 34-pin connector E4 terminal No. 17 (+) (Black/Yellow wire). Figure This is the STA terminal on ECM. Note the voltage reading. Then, measure voltage between ECM 32-pin connector E6 terminal No. 1 (-) and ECM 35-pin connector E5 terminal No. 9 (+) (Pink wire). This is the STAR terminal on ECM. Note the voltage reading. Then, measure voltage between ECM 32-pin connector E6 terminal No. 1 (-) and ECM 32-pin connector E6 terminal No. 12 (+) (Blue/Yellow wire). This is the STSW terminal on ECM. The specified voltage should be 9-14 volts. If voltage is not as specified, go to list below for direction. If voltage is as specified, go to next step.
- If voltage between ECM 32-pin connector E6 terminal No. 1 (-) and ECM connector E4 terminal No. 17 (STA) is zero volts, while the other checks are as specified, go to step 6.
- If voltage between ECM 32-pin connector E6 terminal No. 1 (-) and ECM connector E4 terminal No. 17 (STA) and ECM connector E5 terminal No. 9 (STAR) are both zero volts, while the other check is as specified, replace ECM.
- If all 3 circuits checked are zero volts, go to step 7.
Remove starter relay from engine room relay box. Inspect starter relay. See Fig 1. If relay checks Ok, go to next step. If relay is bad, replace starter relay.
Check the harness and connector between the park/neutral position switch connector and starter relay. Disconnect the park/neutral position switch 9-pin connector. Remove the starter relay from the engine room relay box. Check continuity between park/neutral position switch 9-pin connector terminal No. 6 and starter relay socket terminal No. 1. See Fig 1. Continuity should exist. Then, ensure no continuity exists between ground and starter relay socket terminal No. 1 and No. 2, individually. If continuity is as specified, go to next step. If continuity is not as specified, repair or replace wire and/or connectors as necessary.
Turn ignition on. Measure the voltage between ground and starter relay socket terminal No. 5. If voltage is 9-14 volts, inspect starter assembly and replace if necessary. If voltage is not 9-14 volts, repair or replace wire and/or connectors between starter relay and battery as necessary.

Turn ignition off. Check continuity between specified park/neutral position switch terminals with gearshift lever in specified positions. See PARK/NEUTRAL POSITION SWITCH CONTINUITY . See Figure. If continuity is as specified, repair or replace wires and/or connectors between park/neutral position switch and ECM as necessary. If continuity is not as specified, replace park/neutral position switch.

PARK/NEUTRAL POSITION SWITCH CONTINUITY

Shift Range	Terminals No.
P	1 & 3, 6 & 9
R	2 & 3
N	3 & 5, 6 & 9
D, 4	3 & 7
3	3 & 4
2, L	3 & 8

Check STA No. 2 fuse located in driver's side fuse box. Replace fuse if necessary.
Disconnect ignition switch 8-pin connector. Check continuity between the connector terminals (component side). See Fig 1 for connector terminal selections. If continuity is not as specified, replace ignition switch assembly. If continuity is as specified, repair or replace harness wires and/or connectors between ECM, battery and/or ignition switch as necessary.

Fig 1: Cranking Holding Function Circuit Diagnosis